From 398854c641d479ef7ff37bfdbd1187610bd6f14d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 13:35:42 -0400
Subject: [PATCH 01/25] Added BigInt support to `FibonacciMatrixExpo`

Also added support to `Identity`, `matrixMultiply`, and `matrixExpo`
---
 Maths/Fibonacci.js | 49 ++++++++++++++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 15 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index c1b153f24d..6ff1f0380b 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -75,25 +75,31 @@ const copyMatrix = (A) => {
   return A.map(row => row.map(cell => cell))
 }
 
-const Identity = (size) => {
+// the 2nd param is to generate a "BigInt-safe" matrix
+const Identity = (size, bigint) => {
+  const ZERO = bigint ? 0n : 0
+  const ONE = bigint ? 1n : 1
   const I = Array(size).fill(null).map(() => Array(size).fill())
   return I.map((row, rowIdx) => row.map((_col, colIdx) => {
-    return rowIdx === colIdx ? 1 : 0
+    return rowIdx === colIdx ? ONE : ZERO
   }))
 }
 
 // A of size (l x m) and B of size (m x n)
-// product C will be of size (l x n)
+// product C will be of size (l x n).
+// both matrices must have same-type numeric values
+// either both BigInt or both Number
 const matrixMultiply = (A, B) => {
   A = copyMatrix(A)
   B = copyMatrix(B)
+  const isBigInt = typeof A[0][0] === "bigint"
   const l = A.length
   const m = B.length
   const n = B[0].length // Assuming non-empty matrices
   const C = Array(l).fill(null).map(() => Array(n).fill())
   for (let i = 0; i < l; i++) {
     for (let j = 0; j < n; j++) {
-      C[i][j] = 0
+      C[i][j] = isBigInt ? 0n : 0
       for (let k = 0; k < m; k++) {
         C[i][j] += A[i][k] * B[k][j]
       }
@@ -110,13 +116,17 @@ const matrixMultiply = (A, B) => {
 // A is a square matrix
 const matrixExpo = (A, n) => {
   A = copyMatrix(A)
+  const isBigInt = typeof n === "bigint"
+  const ZERO = isBigInt ? 0n : 0
+  const TWO = isBigInt ? 2n : 2
 
   // Just like Binary exponentiation mentioned in ./BinaryExponentiationIterative.js
   let result = Identity(A.length) // Identity matrix
-  while (n > 0) {
-    if (n % 2 !== 0) result = matrixMultiply(result, A)
-    n = Math.floor(n / 2)
-    if (n > 0) A = matrixMultiply(A, A)
+  while (n > ZERO) {
+    if (n % TWO !== ZERO) result = matrixMultiply(result, A)
+    n /= TWO
+    if (!isBigInt) n = Math.floor(n)
+    if (n > ZERO) A = matrixMultiply(A, A)
   }
   return result
 }
@@ -134,19 +144,28 @@ const FibonacciMatrixExpo = (n) => {
   // or                  F(n, n-1) = A * A * F(n-2, n-3)
   // or                  F(n, n-1) = pow(A, n-1) * F(1, 0)
 
-  if (n === 0) return 0
+  if (n === 0 || n === 0n) return n
+
+  let sign = n < 0
+  if (sign) n = -n
+
+  const isBigInt = typeof n === "bigint"
+  const ZERO = isBigInt ? 0n : 0
+  const ONE = isBigInt ? 1n : 1
 
   const A = [
-    [1, 1],
-    [1, 0]
+    [ONE, ONE],
+    [ONE, ZERO]
   ]
-  const poweredA = matrixExpo(A, n - 1) // A raised to the power n-1
+
+  const poweredA = matrixExpo(A, n - ONE) // A raised to the power n-1
   let F = [
-    [1],
-    [0]
+    [ONE],
+    [ZERO]
   ]
   F = matrixMultiply(poweredA, F)
-  return F[0][0]
+  // https://en.wikipedia.org/wiki/Generalizations_of_Fibonacci_numbers#Extension_to_negative_integers
+  return F[0][0] * (sign ? (-ONE)**(n + ONE) : ONE)
 }
 
 export { FibonacciDpWithoutRecursion }

From ea3966108dc4e1373e94cbc6ba0a3c7174fbb5e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 13:44:09 -0400
Subject: [PATCH 02/25] Fixed style

---
 Maths/Fibonacci.js | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 6ff1f0380b..8e51a7809c 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -92,7 +92,7 @@ const Identity = (size, bigint) => {
 const matrixMultiply = (A, B) => {
   A = copyMatrix(A)
   B = copyMatrix(B)
-  const isBigInt = typeof A[0][0] === "bigint"
+  const isBigInt = typeof A[0][0] === 'bigint'
   const l = A.length
   const m = B.length
   const n = B[0].length // Assuming non-empty matrices
@@ -116,7 +116,7 @@ const matrixMultiply = (A, B) => {
 // A is a square matrix
 const matrixExpo = (A, n) => {
   A = copyMatrix(A)
-  const isBigInt = typeof n === "bigint"
+  const isBigInt = typeof n === 'bigint'
   const ZERO = isBigInt ? 0n : 0
   const TWO = isBigInt ? 2n : 2
 
@@ -146,10 +146,10 @@ const FibonacciMatrixExpo = (n) => {
 
   if (n === 0 || n === 0n) return n
 
-  let sign = n < 0
+  const sign = n < 0
   if (sign) n = -n
 
-  const isBigInt = typeof n === "bigint"
+  const isBigInt = typeof n === 'bigint'
   const ZERO = isBigInt ? 0n : 0
   const ONE = isBigInt ? 1n : 1
 
@@ -165,7 +165,7 @@ const FibonacciMatrixExpo = (n) => {
   ]
   F = matrixMultiply(poweredA, F)
   // https://en.wikipedia.org/wiki/Generalizations_of_Fibonacci_numbers#Extension_to_negative_integers
-  return F[0][0] * (sign ? (-ONE)**(n + ONE) : ONE)
+  return F[0][0] * (sign ? (-ONE) ** (n + ONE) : ONE)
 }
 
 export { FibonacciDpWithoutRecursion }

From 33df07970b27dcb77574212ff93b69305bf29bc8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 14:10:51 -0400
Subject: [PATCH 03/25] Added negatives support to every fn

---
 Maths/Fibonacci.js | 58 ++++++++++++++++++++++++++++++++--------------
 1 file changed, 41 insertions(+), 17 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 8e51a7809c..1c1b0674b5 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -1,13 +1,20 @@
 const list = []
-
+// https://en.wikipedia.org/wiki/Generalizations_of_Fibonacci_numbers#Extension_to_negative_integers
 const FibonacciIterative = (nth) => {
-  const sequence = []
+  const sign = nth < 0
+  if (sign) n = -n
+  const sequence = [0]
 
   if (nth >= 1) sequence.push(1)
-  if (nth >= 2) sequence.push(1)
+  if (nth >= 2) sequence.push(sign ? -1 : 1)
 
   for (let i = 2; i < nth; i++) {
-    sequence.push(sequence[i - 1] + sequence[i - 2])
+    sequence.push(
+      sign ?
+      sequence[i - 2] - sequence[i - 1]
+      :
+      sequence[i - 1] + sequence[i - 2]
+    )
   }
 
   return sequence
@@ -17,7 +24,7 @@ const FibonacciRecursive = (number) => {
   return (() => {
     switch (list.length) {
       case 0:
-        list.push(1)
+        list.push(0)
         return FibonacciRecursive(number)
       case 1:
         list.push(1)
@@ -25,7 +32,13 @@ const FibonacciRecursive = (number) => {
       case number:
         return list
       default:
-        list.push(list[list.length - 1] + list[list.length - 2])
+        const sign = number < 0
+        list.push(
+          sign ?
+          list.at(-2) - list.at(-1)
+          :
+          list.at(-1) + list.at(-2)
+        )
         return FibonacciRecursive(number)
     }
   })()
@@ -34,14 +47,18 @@ const FibonacciRecursive = (number) => {
 const dict = new Map()
 
 const FibonacciRecursiveDP = (stairs) => {
-  if (stairs <= 0) return 0
+  const sign = stairs < 0
+  if (sign) stairs *= -1
+
+  if (stairs === 0) return 0
   if (stairs === 1) return 1
 
   // Memoize stair count
   if (dict.has(stairs)) return dict.get(stairs)
 
-  const res =
-    FibonacciRecursiveDP(stairs - 1) + FibonacciRecursiveDP(stairs - 2)
+  const res = sign
+    ? FibonacciRecursiveDP(stairs - 2) - FibonacciRecursiveDP(stairs - 1)
+    : FibonacciRecursiveDP(stairs - 1) + FibonacciRecursiveDP(stairs - 2)
 
   dict.set(stairs, res)
 
@@ -60,11 +77,18 @@ const FibonacciRecursiveDP = (stairs) => {
 // @Satzyakiz
 
 const FibonacciDpWithoutRecursion = (number) => {
-  const table = []
-  table.push(1)
+  const sgn = number < 0
+  if (sgn) number *= -1
+  const table = [0]
   table.push(1)
+  table.push(sgn ? -1 : 1)
   for (let i = 2; i < number; ++i) {
-    table.push(table[i - 1] + table[i - 2])
+    table.push(
+      sgn ?
+      table[i - 2] - table[i - 1]
+      :
+      table[i - 1] + table[i - 2]
+    )
   }
   return table
 }
@@ -75,10 +99,11 @@ const copyMatrix = (A) => {
   return A.map(row => row.map(cell => cell))
 }
 
-// the 2nd param is to generate a "BigInt-safe" matrix
-const Identity = (size, bigint) => {
-  const ZERO = bigint ? 0n : 0
-  const ONE = bigint ? 1n : 1
+const Identity = (size) => {
+  const isBigInt = typeof size === 'bigint'
+  const ZERO = isBigInt ? 0n : 0
+  const ONE = isBigInt ? 1n : 1
+  size = Number(size)
   const I = Array(size).fill(null).map(() => Array(size).fill())
   return I.map((row, rowIdx) => row.map((_col, colIdx) => {
     return rowIdx === colIdx ? ONE : ZERO
@@ -164,7 +189,6 @@ const FibonacciMatrixExpo = (n) => {
     [ZERO]
   ]
   F = matrixMultiply(poweredA, F)
-  // https://en.wikipedia.org/wiki/Generalizations_of_Fibonacci_numbers#Extension_to_negative_integers
   return F[0][0] * (sign ? (-ONE) ** (n + ONE) : ONE)
 }
 

From f4f1d5328855d06a87b0820584276a7bb464f377 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 14:16:25 -0400
Subject: [PATCH 04/25] Fixed bug

---
 Maths/Fibonacci.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 1c1b0674b5..5d699aa3e0 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -146,7 +146,7 @@ const matrixExpo = (A, n) => {
   const TWO = isBigInt ? 2n : 2
 
   // Just like Binary exponentiation mentioned in ./BinaryExponentiationIterative.js
-  let result = Identity(A.length) // Identity matrix
+  let result = Identity((isBigInt ? BigInt : Number)(A.length)) // Identity matrix
   while (n > ZERO) {
     if (n % TWO !== ZERO) result = matrixMultiply(result, A)
     n /= TWO

From 2bcbc58898825be6814951cc43669c48baaa49be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 14:25:45 -0400
Subject: [PATCH 05/25] Added all missing tests

---
 Maths/test/Fibonacci.test.js | 47 +++++++++++++++++++++++++++++++-----
 1 file changed, 41 insertions(+), 6 deletions(-)

diff --git a/Maths/test/Fibonacci.test.js b/Maths/test/Fibonacci.test.js
index bccd799be9..dfea5a603c 100644
--- a/Maths/test/Fibonacci.test.js
+++ b/Maths/test/Fibonacci.test.js
@@ -8,24 +8,34 @@ import {
 
 describe('Fibonacci', () => {
   it('should return an array of numbers for FibonacciIterative', () => {
-    expect(FibonacciIterative(5)).toEqual(
-      expect.arrayContaining([1, 1, 2, 3, 5])
+    expect(FibonacciIterative(6)).toEqual(
+      expect.arrayContaining([0, 1, 1, 2, 3, 5, 8])
+    )
+    expect(FibonacciIterative(-6)).toEqual(
+      expect.arrayContaining([0, 1, -1, 2, -3, 5, -8])
     )
   })
 
   it('should return an array of numbers for FibonacciRecursive', () => {
-    expect(FibonacciRecursive(5)).toEqual(
-      expect.arrayContaining([1, 1, 2, 3, 5])
+    expect(FibonacciRecursive(6)).toEqual(
+      expect.arrayContaining([0, 1, 1, 2, 3, 5, 8])
+    )
+    expect(FibonacciRecursive(-6)).toEqual(
+      expect.arrayContaining([0, 1, -1, 2, -3, 5, -8])
     )
   })
 
   it('should return number for FibonacciRecursiveDP', () => {
     expect(FibonacciRecursiveDP(5)).toBe(5)
+    expect(FibonacciRecursiveDP(-6)).toBe(-8)
   })
 
   it('should return an array of numbers for FibonacciDpWithoutRecursion', () => {
-    expect(FibonacciDpWithoutRecursion(5)).toEqual(
-      expect.arrayContaining([1, 1, 2, 3, 5])
+    expect(FibonacciDpWithoutRecursion(6)).toEqual(
+      expect.arrayContaining([0, 1, 1, 2, 3, 5, 8])
+    )
+    expect(FibonacciDpWithoutRecursion(-6)).toEqual(
+      expect.arrayContaining([0, 1, -1, 2, -3, 5, -8])
     )
   })
 
@@ -36,5 +46,30 @@ describe('Fibonacci', () => {
     expect(FibonacciMatrixExpo(3)).toBe(2)
     expect(FibonacciMatrixExpo(4)).toBe(3)
     expect(FibonacciMatrixExpo(5)).toBe(5)
+    expect(FibonacciMatrixExpo(6)).toBe(8)
+    
+    expect(FibonacciMatrixExpo(0n)).toBe(0n)
+    expect(FibonacciMatrixExpo(1n)).toBe(1n)
+    expect(FibonacciMatrixExpo(2n)).toBe(1n)
+    expect(FibonacciMatrixExpo(3n)).toBe(2n)
+    expect(FibonacciMatrixExpo(4n)).toBe(3n)
+    expect(FibonacciMatrixExpo(5n)).toBe(5n)
+    expect(FibonacciMatrixExpo(6n)).toBe(8n)
+    
+    expect(FibonacciMatrixExpo(-0)).toBe(-0)
+    expect(FibonacciMatrixExpo(-1)).toBe(1)
+    expect(FibonacciMatrixExpo(-2)).toBe(-1)
+    expect(FibonacciMatrixExpo(-3)).toBe(2)
+    expect(FibonacciMatrixExpo(-4)).toBe(-3)
+    expect(FibonacciMatrixExpo(-5)).toBe(5)
+    expect(FibonacciMatrixExpo(-6)).toBe(-8)
+    
+    expect(FibonacciMatrixExpo(-0n)).toBe(0n)
+    expect(FibonacciMatrixExpo(-1n)).toBe(1n)
+    expect(FibonacciMatrixExpo(-2n)).toBe(-1n)
+    expect(FibonacciMatrixExpo(-3n)).toBe(2n)
+    expect(FibonacciMatrixExpo(-4n)).toBe(-3n)
+    expect(FibonacciMatrixExpo(-5n)).toBe(5n)
+    expect(FibonacciMatrixExpo(-6n)).toBe(-8n)
   })
 })

From 3d865f3bf1d11615a11da8159030b66f249f806c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 14:30:15 -0400
Subject: [PATCH 06/25] Splitted `BigInt` & `Number` tests

---
 Maths/test/Fibonacci.test.js | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/Maths/test/Fibonacci.test.js b/Maths/test/Fibonacci.test.js
index dfea5a603c..0812de4544 100644
--- a/Maths/test/Fibonacci.test.js
+++ b/Maths/test/Fibonacci.test.js
@@ -47,15 +47,7 @@ describe('Fibonacci', () => {
     expect(FibonacciMatrixExpo(4)).toBe(3)
     expect(FibonacciMatrixExpo(5)).toBe(5)
     expect(FibonacciMatrixExpo(6)).toBe(8)
-    
-    expect(FibonacciMatrixExpo(0n)).toBe(0n)
-    expect(FibonacciMatrixExpo(1n)).toBe(1n)
-    expect(FibonacciMatrixExpo(2n)).toBe(1n)
-    expect(FibonacciMatrixExpo(3n)).toBe(2n)
-    expect(FibonacciMatrixExpo(4n)).toBe(3n)
-    expect(FibonacciMatrixExpo(5n)).toBe(5n)
-    expect(FibonacciMatrixExpo(6n)).toBe(8n)
-    
+
     expect(FibonacciMatrixExpo(-0)).toBe(-0)
     expect(FibonacciMatrixExpo(-1)).toBe(1)
     expect(FibonacciMatrixExpo(-2)).toBe(-1)
@@ -63,7 +55,17 @@ describe('Fibonacci', () => {
     expect(FibonacciMatrixExpo(-4)).toBe(-3)
     expect(FibonacciMatrixExpo(-5)).toBe(5)
     expect(FibonacciMatrixExpo(-6)).toBe(-8)
-    
+  })
+  
+  it('should return bigint for FibonacciMatrixExpo', () => {
+    expect(FibonacciMatrixExpo(0n)).toBe(0n)
+    expect(FibonacciMatrixExpo(1n)).toBe(1n)
+    expect(FibonacciMatrixExpo(2n)).toBe(1n)
+    expect(FibonacciMatrixExpo(3n)).toBe(2n)
+    expect(FibonacciMatrixExpo(4n)).toBe(3n)
+    expect(FibonacciMatrixExpo(5n)).toBe(5n)
+    expect(FibonacciMatrixExpo(6n)).toBe(8n)
+
     expect(FibonacciMatrixExpo(-0n)).toBe(0n)
     expect(FibonacciMatrixExpo(-1n)).toBe(1n)
     expect(FibonacciMatrixExpo(-2n)).toBe(-1n)

From 0dc81a8fa0efb8a18f1a291e4170f8b3c6352586 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 14:37:22 -0400
Subject: [PATCH 07/25] Shortened `sign` to `sgn` in most (not all) places

---
 Maths/Fibonacci.js | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 5d699aa3e0..314c9a2c40 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -32,9 +32,9 @@ const FibonacciRecursive = (number) => {
       case number:
         return list
       default:
-        const sign = number < 0
+        const sgn = number < 0
         list.push(
-          sign ?
+          sgn ?
           list.at(-2) - list.at(-1)
           :
           list.at(-1) + list.at(-2)
@@ -47,8 +47,8 @@ const FibonacciRecursive = (number) => {
 const dict = new Map()
 
 const FibonacciRecursiveDP = (stairs) => {
-  const sign = stairs < 0
-  if (sign) stairs *= -1
+  const sgn = stairs < 0
+  if (sgn) stairs *= -1
 
   if (stairs === 0) return 0
   if (stairs === 1) return 1
@@ -56,7 +56,7 @@ const FibonacciRecursiveDP = (stairs) => {
   // Memoize stair count
   if (dict.has(stairs)) return dict.get(stairs)
 
-  const res = sign
+  const res = sgn
     ? FibonacciRecursiveDP(stairs - 2) - FibonacciRecursiveDP(stairs - 1)
     : FibonacciRecursiveDP(stairs - 1) + FibonacciRecursiveDP(stairs - 2)
 
@@ -171,8 +171,8 @@ const FibonacciMatrixExpo = (n) => {
 
   if (n === 0 || n === 0n) return n
 
-  const sign = n < 0
-  if (sign) n = -n
+  const sgn = n < 0
+  if (sgn) n = -n
 
   const isBigInt = typeof n === 'bigint'
   const ZERO = isBigInt ? 0n : 0
@@ -189,7 +189,7 @@ const FibonacciMatrixExpo = (n) => {
     [ZERO]
   ]
   F = matrixMultiply(poweredA, F)
-  return F[0][0] * (sign ? (-ONE) ** (n + ONE) : ONE)
+  return F[0][0] * (sgn ? (-ONE) ** (n + ONE) : ONE)
 }
 
 export { FibonacciDpWithoutRecursion }

From 1f61f5173b36b2a612637ca7944a61e7f100fe68 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 14:48:13 -0400
Subject: [PATCH 08/25] Fixed indexing

---
 Maths/Fibonacci.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 314c9a2c40..406c1babde 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -29,7 +29,7 @@ const FibonacciRecursive = (number) => {
       case 1:
         list.push(1)
         return FibonacciRecursive(number)
-      case number:
+      case number + 1:
         return list
       default:
         const sgn = number < 0

From 7090d5aca46bb38923913ecd00d1d240cfc9381f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 15:00:15 -0400
Subject: [PATCH 09/25] Fixed bug at FDPWR

---
 Maths/Fibonacci.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 406c1babde..0def7b7827 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -85,9 +85,9 @@ const FibonacciDpWithoutRecursion = (number) => {
   for (let i = 2; i < number; ++i) {
     table.push(
       sgn ?
-      table[i - 2] - table[i - 1]
+      table[i - 1] - table[i]
       :
-      table[i - 1] + table[i - 2]
+      table[i] + table[i - 1]
     )
   }
   return table

From 03ed1f823e1516d93cd6e6705495a786a6f8abbd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 15:01:19 -0400
Subject: [PATCH 10/25] Fixed FRDP

---
 Maths/Fibonacci.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 0def7b7827..55691cf96e 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -57,8 +57,8 @@ const FibonacciRecursiveDP = (stairs) => {
   if (dict.has(stairs)) return dict.get(stairs)
 
   const res = sgn
-    ? FibonacciRecursiveDP(stairs - 2) - FibonacciRecursiveDP(stairs - 1)
-    : FibonacciRecursiveDP(stairs - 1) + FibonacciRecursiveDP(stairs - 2)
+    ? FibonacciRecursiveDP(stairs - 1) - FibonacciRecursiveDP(stairs)
+    : FibonacciRecursiveDP(stairs) + FibonacciRecursiveDP(stairs - 1)
 
   dict.set(stairs, res)
 

From b2101fcbd9dd6e55e92e2529dbeab28c5c6fcb5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 15:02:34 -0400
Subject: [PATCH 11/25] Fixed F iter

---
 Maths/Fibonacci.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 55691cf96e..dd20b3fb6e 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -11,9 +11,9 @@ const FibonacciIterative = (nth) => {
   for (let i = 2; i < nth; i++) {
     sequence.push(
       sign ?
-      sequence[i - 2] - sequence[i - 1]
+      sequence[i - 1] - sequence[i]
       :
-      sequence[i - 1] + sequence[i - 2]
+      sequence[i] + sequence[i - 1]
     )
   }
 

From c5fe0b5202dc23dad9166aa7a78b95973eca8466 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 15:14:53 -0400
Subject: [PATCH 12/25] Fixed FRDP again

---
 Maths/Fibonacci.js | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index dd20b3fb6e..ade9920e16 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -50,15 +50,14 @@ const FibonacciRecursiveDP = (stairs) => {
   const sgn = stairs < 0
   if (sgn) stairs *= -1
 
-  if (stairs === 0) return 0
-  if (stairs === 1) return 1
+  if (stairs <= 1) return stairs
 
   // Memoize stair count
   if (dict.has(stairs)) return dict.get(stairs)
 
   const res = sgn
-    ? FibonacciRecursiveDP(stairs - 1) - FibonacciRecursiveDP(stairs)
-    : FibonacciRecursiveDP(stairs) + FibonacciRecursiveDP(stairs - 1)
+    ? FibonacciRecursiveDP(stairs - 2) - FibonacciRecursiveDP(stairs - 1)
+    : FibonacciRecursiveDP(stairs - 1) + FibonacciRecursiveDP(stairs - 2)
 
   dict.set(stairs, res)
 

From 787fd75680b8ebbfb9db930e6126d76bf3ee2687 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 15:39:38 -0400
Subject: [PATCH 13/25] Added `FibonacciGenerator`

This wasn't originally part of the PR, but I thought it would be good to add
---
 Maths/Fibonacci.js | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index ade9920e16..7dc6d7e4dd 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -1,4 +1,3 @@
-const list = []
 // https://en.wikipedia.org/wiki/Generalizations_of_Fibonacci_numbers#Extension_to_negative_integers
 const FibonacciIterative = (nth) => {
   const sign = nth < 0
@@ -20,7 +19,20 @@ const FibonacciIterative = (nth) => {
   return sequence
 }
 
+const FibonacciGenerator = function* (sign) {
+  let a = 0
+  let b = 1
+  yield a
+  while (true) {
+    yield b
+    [a, b] = sign ? [b, a - b] : [b, a + b]
+  }
+}
+
+const list = []
 const FibonacciRecursive = (number) => {
+  const sgn = number < 0
+  if (sgn) number *= -1
   return (() => {
     switch (list.length) {
       case 0:
@@ -32,7 +44,6 @@ const FibonacciRecursive = (number) => {
       case number + 1:
         return list
       default:
-        const sgn = number < 0
         list.push(
           sgn ?
           list.at(-2) - list.at(-1)
@@ -45,7 +56,6 @@ const FibonacciRecursive = (number) => {
 }
 
 const dict = new Map()
-
 const FibonacciRecursiveDP = (stairs) => {
   const sgn = stairs < 0
   if (sgn) stairs *= -1
@@ -193,6 +203,7 @@ const FibonacciMatrixExpo = (n) => {
 
 export { FibonacciDpWithoutRecursion }
 export { FibonacciIterative }
+export { FibonacciGenerator }
 export { FibonacciRecursive }
 export { FibonacciRecursiveDP }
 export { FibonacciMatrixExpo }

From c11856bf635d26861a368d13fc6fb23f57da9282 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 15:44:08 -0400
Subject: [PATCH 14/25] Added tests for `FibonacciGenerator`

---
 Maths/test/Fibonacci.test.js | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/Maths/test/Fibonacci.test.js b/Maths/test/Fibonacci.test.js
index 0812de4544..05d8d2e741 100644
--- a/Maths/test/Fibonacci.test.js
+++ b/Maths/test/Fibonacci.test.js
@@ -2,6 +2,7 @@ import {
   FibonacciDpWithoutRecursion,
   FibonacciRecursiveDP,
   FibonacciIterative,
+  FibonacciGenerator,
   FibonacciRecursive,
   FibonacciMatrixExpo
 } from '../Fibonacci'
@@ -16,6 +17,26 @@ describe('Fibonacci', () => {
     )
   })
 
+  it('should return number for FibonacciGenerator', () => {
+    const positive = FibonacciGenerator()
+    expect(positive.next().value).toBe(0)
+    expect(positive.next().value).toBe(1)
+    expect(positive.next().value).toBe(1)
+    expect(positive.next().value).toBe(2)
+    expect(positive.next().value).toBe(3)
+    expect(positive.next().value).toBe(5)
+    expect(positive.next().value).toBe(8)
+    
+    const negative = FibonacciGenerator(true)
+    expect(negative.next().value).toBe(0)
+    expect(negative.next().value).toBe(1)
+    expect(negative.next().value).toBe(-1)
+    expect(negative.next().value).toBe(2)
+    expect(negative.next().value).toBe(-3)
+    expect(negative.next().value).toBe(5)
+    expect(negative.next().value).toBe(-8)
+  })
+
   it('should return an array of numbers for FibonacciRecursive', () => {
     expect(FibonacciRecursive(6)).toEqual(
       expect.arrayContaining([0, 1, 1, 2, 3, 5, 8])

From 028ebe9d046aa7bb519e015406c90c5a41721658 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 15:44:56 -0400
Subject: [PATCH 15/25] More consistent test

---
 Maths/test/Fibonacci.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Maths/test/Fibonacci.test.js b/Maths/test/Fibonacci.test.js
index 05d8d2e741..143e99401f 100644
--- a/Maths/test/Fibonacci.test.js
+++ b/Maths/test/Fibonacci.test.js
@@ -47,7 +47,7 @@ describe('Fibonacci', () => {
   })
 
   it('should return number for FibonacciRecursiveDP', () => {
-    expect(FibonacciRecursiveDP(5)).toBe(5)
+    expect(FibonacciRecursiveDP(6)).toBe(8)
     expect(FibonacciRecursiveDP(-6)).toBe(-8)
   })
 

From 69bbe51cef0259cc23b7a9f629d69df594728927 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 15:56:19 -0400
Subject: [PATCH 16/25] Fixed FRDP yet again

---
 Maths/Fibonacci.js | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 7dc6d7e4dd..99c195ac40 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -19,13 +19,13 @@ const FibonacciIterative = (nth) => {
   return sequence
 }
 
-const FibonacciGenerator = function* (sign) {
+const FibonacciGenerator = function* (negative) {
   let a = 0
   let b = 1
   yield a
   while (true) {
     yield b
-    [a, b] = sign ? [b, a - b] : [b, a + b]
+    [a, b] = negative ? [b, a - b] : [b, a + b]
   }
 }
 
@@ -63,15 +63,13 @@ const FibonacciRecursiveDP = (stairs) => {
   if (stairs <= 1) return stairs
 
   // Memoize stair count
-  if (dict.has(stairs)) return dict.get(stairs)
+  if (dict.has(stairs)) return (sgn ? (-1) ** (stairs + 1) : 1) * dict.get(stairs)
 
-  const res = sgn
-    ? FibonacciRecursiveDP(stairs - 2) - FibonacciRecursiveDP(stairs - 1)
-    : FibonacciRecursiveDP(stairs - 1) + FibonacciRecursiveDP(stairs - 2)
+  const res = FibonacciRecursiveDP(stairs - 1) + FibonacciRecursiveDP(stairs - 2)
 
   dict.set(stairs, res)
 
-  return res
+  return (sgn ? (-1) ** (stairs + 1) : 1) * res
 }
 
 // Algorithms

From 6f0de19f96154bf79bcf0123c30ee90c29aa941d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 16:06:15 -0400
Subject: [PATCH 17/25] Fixed Fib recursive

---
 Maths/Fibonacci.js | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 99c195ac40..bed7331bbe 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -44,15 +44,10 @@ const FibonacciRecursive = (number) => {
       case number + 1:
         return list
       default:
-        list.push(
-          sgn ?
-          list.at(-2) - list.at(-1)
-          :
-          list.at(-1) + list.at(-2)
-        )
+        list.push(list.at(-1) + list.at(-2))
         return FibonacciRecursive(number)
     }
-  })()
+  })().map((fib, i) => fib * (sgn ? (-1) ** (i + 1) : 1))
 }
 
 const dict = new Map()

From 82861ef86c2efde22bd688a1113220e5a499d142 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 16:11:30 -0400
Subject: [PATCH 18/25] Explicitly using negative 0

---
 Maths/test/Fibonacci.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Maths/test/Fibonacci.test.js b/Maths/test/Fibonacci.test.js
index 143e99401f..987dedd103 100644
--- a/Maths/test/Fibonacci.test.js
+++ b/Maths/test/Fibonacci.test.js
@@ -42,7 +42,7 @@ describe('Fibonacci', () => {
       expect.arrayContaining([0, 1, 1, 2, 3, 5, 8])
     )
     expect(FibonacciRecursive(-6)).toEqual(
-      expect.arrayContaining([0, 1, -1, 2, -3, 5, -8])
+      expect.arrayContaining([-0, 1, -1, 2, -3, 5, -8])
     )
   })
 

From 83afc56314db8c0742466b24ebaeaae59374ce1c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 16:16:36 -0400
Subject: [PATCH 19/25] Fixed errors

---
 Maths/Fibonacci.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index bed7331bbe..41b488c261 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -1,7 +1,7 @@
 // https://en.wikipedia.org/wiki/Generalizations_of_Fibonacci_numbers#Extension_to_negative_integers
 const FibonacciIterative = (nth) => {
   const sign = nth < 0
-  if (sign) n = -n
+  if (sign) nth = -nth
   const sequence = [0]
 
   if (nth >= 1) sequence.push(1)
@@ -24,7 +24,7 @@ const FibonacciGenerator = function* (negative) {
   let b = 1
   yield a
   while (true) {
-    yield b
+    yield b;
     [a, b] = negative ? [b, a - b] : [b, a + b]
   }
 }

From a034743b238d939e91edac8826e0a4983a50a621 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 16:25:57 -0400
Subject: [PATCH 20/25] Fixed part of style

---
 Maths/Fibonacci.js | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 41b488c261..f5ff620a2b 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -9,17 +9,16 @@ const FibonacciIterative = (nth) => {
 
   for (let i = 2; i < nth; i++) {
     sequence.push(
-      sign ?
-      sequence[i - 1] - sequence[i]
-      :
-      sequence[i] + sequence[i - 1]
+      sign
+      ? sequence[i - 1] - sequence[i]
+      : sequence[i] + sequence[i - 1]
     )
   }
 
   return sequence
 }
 
-const FibonacciGenerator = function* (negative) {
+const FibonacciGenerator = function * (negative) {
   let a = 0
   let b = 1
   yield a
@@ -86,10 +85,9 @@ const FibonacciDpWithoutRecursion = (number) => {
   table.push(sgn ? -1 : 1)
   for (let i = 2; i < number; ++i) {
     table.push(
-      sgn ?
-      table[i - 1] - table[i]
-      :
-      table[i] + table[i - 1]
+      sgn
+      ? table[i - 1] - table[i]
+      : table[i] + table[i - 1]
     )
   }
   return table

From cdbf5ff5c20314b38274da40a089d5e3aacf34fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Tue, 21 Jun 2022 16:30:15 -0400
Subject: [PATCH 21/25] Fixed style

---
 Maths/Fibonacci.js | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index f5ff620a2b..1810434d2c 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -9,9 +9,7 @@ const FibonacciIterative = (nth) => {
 
   for (let i = 2; i < nth; i++) {
     sequence.push(
-      sign
-      ? sequence[i - 1] - sequence[i]
-      : sequence[i] + sequence[i - 1]
+      sign ? sequence[i - 1] - sequence[i] : sequence[i] + sequence[i - 1]
     )
   }
 
@@ -85,9 +83,7 @@ const FibonacciDpWithoutRecursion = (number) => {
   table.push(sgn ? -1 : 1)
   for (let i = 2; i < number; ++i) {
     table.push(
-      sgn
-      ? table[i - 1] - table[i]
-      : table[i] + table[i - 1]
+      sgn ? table[i - 1] - table[i] : table[i] + table[i - 1]
     )
   }
   return table

From 79d4c47b4d0299a495f351b8d8fc5c326195ad60 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Wed, 22 Jun 2022 01:36:00 -0400
Subject: [PATCH 22/25] Ran `npx standard --fix Fibonacci.js`


From 42d3ae43ec5ed6f8ec5f18ce43c4d4fc65296677 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Wed, 22 Jun 2022 01:41:52 -0400
Subject: [PATCH 23/25] Removed trailing space

---
 Maths/test/Fibonacci.test.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Maths/test/Fibonacci.test.js b/Maths/test/Fibonacci.test.js
index 987dedd103..f3dcb98fe7 100644
--- a/Maths/test/Fibonacci.test.js
+++ b/Maths/test/Fibonacci.test.js
@@ -26,7 +26,7 @@ describe('Fibonacci', () => {
     expect(positive.next().value).toBe(3)
     expect(positive.next().value).toBe(5)
     expect(positive.next().value).toBe(8)
-    
+
     const negative = FibonacciGenerator(true)
     expect(negative.next().value).toBe(0)
     expect(negative.next().value).toBe(1)
@@ -77,7 +77,7 @@ describe('Fibonacci', () => {
     expect(FibonacciMatrixExpo(-5)).toBe(5)
     expect(FibonacciMatrixExpo(-6)).toBe(-8)
   })
-  
+
   it('should return bigint for FibonacciMatrixExpo', () => {
     expect(FibonacciMatrixExpo(0n)).toBe(0n)
     expect(FibonacciMatrixExpo(1n)).toBe(1n)

From 21ff3fdb25ef70d53af186a38a4222f8639fdbfe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Sun, 26 Jun 2022 14:01:14 -0400
Subject: [PATCH 24/25] Update Fibonacci.js

---
 Maths/Fibonacci.js | 59 +++++++++++++++++++++++-----------------------
 1 file changed, 29 insertions(+), 30 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 1810434d2c..1186e023e2 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -1,48 +1,48 @@
 // https://en.wikipedia.org/wiki/Generalizations_of_Fibonacci_numbers#Extension_to_negative_integers
-const FibonacciIterative = (nth) => {
-  const sign = nth < 0
-  if (sign) nth = -nth
+const FibonacciIterative = (num) => {
+  const isNeg = num < 0
+  if (isNeg) num *= -1
   const sequence = [0]
 
-  if (nth >= 1) sequence.push(1)
-  if (nth >= 2) sequence.push(sign ? -1 : 1)
+  if (num >= 1) sequence.push(1)
+  if (num >= 2) sequence.push(isNeg ? -1 : 1)
 
-  for (let i = 2; i < nth; i++) {
+  for (let i = 2; i < num; i++) {
     sequence.push(
-      sign ? sequence[i - 1] - sequence[i] : sequence[i] + sequence[i - 1]
+      isNeg ? sequence[i - 1] - sequence[i] : sequence[i] + sequence[i - 1]
     )
   }
 
   return sequence
 }
 
-const FibonacciGenerator = function * (negative) {
+const FibonacciGenerator = function * (neg) {
   let a = 0
   let b = 1
   yield a
   while (true) {
     yield b;
-    [a, b] = negative ? [b, a - b] : [b, a + b]
+    [a, b] = neg ? [b, a - b] : [b, a + b]
   }
 }
 
 const list = []
-const FibonacciRecursive = (number) => {
-  const sgn = number < 0
-  if (sgn) number *= -1
+const FibonacciRecursive = (num) => {
+  const sgn = num < 0
+  if (sgn) num *= -1
   return (() => {
     switch (list.length) {
       case 0:
         list.push(0)
-        return FibonacciRecursive(number)
+        return FibonacciRecursive(num)
       case 1:
         list.push(1)
-        return FibonacciRecursive(number)
-      case number + 1:
+        return FibonacciRecursive(num)
+      case num + 1:
         return list
       default:
         list.push(list.at(-1) + list.at(-2))
-        return FibonacciRecursive(number)
+        return FibonacciRecursive(num)
     }
   })().map((fib, i) => fib * (sgn ? (-1) ** (i + 1) : 1))
 }
@@ -75,13 +75,13 @@ const FibonacciRecursiveDP = (stairs) => {
 // a function of the number of input bits
 // @Satzyakiz
 
-const FibonacciDpWithoutRecursion = (number) => {
-  const sgn = number < 0
-  if (sgn) number *= -1
+const FibonacciDpWithoutRecursion = (num) => {
+  const sgn = num < 0
+  if (sgn) num *= -1
   const table = [0]
   table.push(1)
   table.push(sgn ? -1 : 1)
-  for (let i = 2; i < number; ++i) {
+  for (let i = 2; i < num; ++i) {
     table.push(
       sgn ? table[i - 1] - table[i] : table[i] + table[i - 1]
     )
@@ -152,7 +152,10 @@ const matrixExpo = (A, n) => {
   return result
 }
 
-const FibonacciMatrixExpo = (n) => {
+const FibonacciMatrixExpo = (num) => {
+  const isBigInt = typeof num === 'bigint'
+  const ZERO = isBigInt ? 0n : 0
+  const ONE = isBigInt ? 1n : 1
   // F(0) = 0, F(1) = 1
   // F(n) = F(n-1) + F(n-2)
   // Consider below matrix multiplication:
@@ -165,27 +168,23 @@ const FibonacciMatrixExpo = (n) => {
   // or                  F(n, n-1) = A * A * F(n-2, n-3)
   // or                  F(n, n-1) = pow(A, n-1) * F(1, 0)
 
-  if (n === 0 || n === 0n) return n
-
-  const sgn = n < 0
-  if (sgn) n = -n
+  if (num === ZERO) return num
 
-  const isBigInt = typeof n === 'bigint'
-  const ZERO = isBigInt ? 0n : 0
-  const ONE = isBigInt ? 1n : 1
+  const sgn = num < 0
+  if (sgn) num *= -ONE
 
   const A = [
     [ONE, ONE],
     [ONE, ZERO]
   ]
 
-  const poweredA = matrixExpo(A, n - ONE) // A raised to the power n-1
+  const poweredA = matrixExpo(A, num - ONE) // A raised to the power n-1
   let F = [
     [ONE],
     [ZERO]
   ]
   F = matrixMultiply(poweredA, F)
-  return F[0][0] * (sgn ? (-ONE) ** (n + ONE) : ONE)
+  return F[0][0] * (sgn ? (-ONE) ** (num + ONE) : ONE)
 }
 
 export { FibonacciDpWithoutRecursion }

From 81e64a431a45918a9e980896276d9df0d3f0446c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Fern=C3=A1ndez=20Serrata?=
 <76864299+Rudxain@users.noreply.github.com>
Date: Sun, 26 Jun 2022 14:06:22 -0400
Subject: [PATCH 25/25] Update Fibonacci.js

---
 Maths/Fibonacci.js | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/Maths/Fibonacci.js b/Maths/Fibonacci.js
index 1186e023e2..fc8102ad2c 100644
--- a/Maths/Fibonacci.js
+++ b/Maths/Fibonacci.js
@@ -28,8 +28,8 @@ const FibonacciGenerator = function * (neg) {
 
 const list = []
 const FibonacciRecursive = (num) => {
-  const sgn = num < 0
-  if (sgn) num *= -1
+  const isNeg = num < 0
+  if (isNeg) num *= -1
   return (() => {
     switch (list.length) {
       case 0:
@@ -44,24 +44,24 @@ const FibonacciRecursive = (num) => {
         list.push(list.at(-1) + list.at(-2))
         return FibonacciRecursive(num)
     }
-  })().map((fib, i) => fib * (sgn ? (-1) ** (i + 1) : 1))
+  })().map((fib, i) => fib * (isNeg ? (-1) ** (i + 1) : 1))
 }
 
 const dict = new Map()
 const FibonacciRecursiveDP = (stairs) => {
-  const sgn = stairs < 0
-  if (sgn) stairs *= -1
+  const isNeg = stairs < 0
+  if (isNeg) stairs *= -1
 
   if (stairs <= 1) return stairs
 
   // Memoize stair count
-  if (dict.has(stairs)) return (sgn ? (-1) ** (stairs + 1) : 1) * dict.get(stairs)
+  if (dict.has(stairs)) return (isNeg ? (-1) ** (stairs + 1) : 1) * dict.get(stairs)
 
   const res = FibonacciRecursiveDP(stairs - 1) + FibonacciRecursiveDP(stairs - 2)
 
   dict.set(stairs, res)
 
-  return (sgn ? (-1) ** (stairs + 1) : 1) * res
+  return (isNeg ? (-1) ** (stairs + 1) : 1) * res
 }
 
 // Algorithms
@@ -76,14 +76,14 @@ const FibonacciRecursiveDP = (stairs) => {
 // @Satzyakiz
 
 const FibonacciDpWithoutRecursion = (num) => {
-  const sgn = num < 0
-  if (sgn) num *= -1
+  const isNeg = num < 0
+  if (isNeg) num *= -1
   const table = [0]
   table.push(1)
-  table.push(sgn ? -1 : 1)
+  table.push(isNeg ? -1 : 1)
   for (let i = 2; i < num; ++i) {
     table.push(
-      sgn ? table[i - 1] - table[i] : table[i] + table[i - 1]
+      isNeg ? table[i - 1] - table[i] : table[i] + table[i - 1]
     )
   }
   return table
@@ -170,8 +170,8 @@ const FibonacciMatrixExpo = (num) => {
 
   if (num === ZERO) return num
 
-  const sgn = num < 0
-  if (sgn) num *= -ONE
+  const isNeg = num < 0
+  if (isNeg) num *= -ONE
 
   const A = [
     [ONE, ONE],
@@ -184,7 +184,7 @@ const FibonacciMatrixExpo = (num) => {
     [ZERO]
   ]
   F = matrixMultiply(poweredA, F)
-  return F[0][0] * (sgn ? (-ONE) ** (num + ONE) : ONE)
+  return F[0][0] * (isNeg ? (-ONE) ** (num + ONE) : ONE)
 }
 
 export { FibonacciDpWithoutRecursion }