From 1c828f2ab15a685d1a41c31ddc3b1a31acec75e1 Mon Sep 17 00:00:00 2001
From: emyarod <afw5059@gmail.com>
Date: Tue, 27 Feb 2018 10:16:52 -0500
Subject: [PATCH 1/2] Add O(n) maximum subarray test

---
 test/searching/maximum-subarray.spec.js | 29 +++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 test/searching/maximum-subarray.spec.js

diff --git a/test/searching/maximum-subarray.spec.js b/test/searching/maximum-subarray.spec.js
new file mode 100644
index 00000000..66daa8c7
--- /dev/null
+++ b/test/searching/maximum-subarray.spec.js
@@ -0,0 +1,29 @@
+var maxSubArray = require('../../src/searching/maximum-subarray').maxSubarray;
+
+describe('Maximum subarray', function() {
+  'use strict';
+
+  it('should work with empty arrays', function() {
+    expect(maxSubArray([])).toBeUndefined();
+  });
+
+  it('should return the only element when an array with single element is passed', function() {
+    expect(maxSubArray([42])).toBe(42);
+  });
+
+  it('should return the only negative element when an array with single element is passed', function() {
+    expect(maxSubArray([-42])).toBe(-42);
+  });
+
+  it('should return the zero when an array with single element, which is zero is passed', function() {
+    expect(maxSubArray([0])).toBe(0);
+  });
+
+  it('should return the max sum of a subarray', function() {
+    expect(maxSubArray([1, -1, 2, 3, -1])).toBe(5);
+  });
+
+  it('should return the max negative number when array with negative numbers is provided', function() {
+    expect(maxSubArray([-10, -1, -2, -3, -1])).toBe(-1);
+  });
+});

From 1fe106d531b442d06777faee9c2cd98d7b6e3247 Mon Sep 17 00:00:00 2001
From: emyarod <afw5059@gmail.com>
Date: Tue, 27 Feb 2018 10:17:06 -0500
Subject: [PATCH 2/2] Fix O(n) maximum subarray solution

---
 src/searching/maximum-subarray.js | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/searching/maximum-subarray.js b/src/searching/maximum-subarray.js
index 4628369e..85ae9d11 100644
--- a/src/searching/maximum-subarray.js
+++ b/src/searching/maximum-subarray.js
@@ -20,11 +20,10 @@
    * @return {Number} Maximum sum of the elements of a subarray.
    */
   function maxSubarray(array) {
-    var currentMax = 0;
-    var max = 0;
-
-    for (var i = 0; i < array.length; i += 1) {
-      currentMax = Math.max(0, currentMax + array[i]);
+    var currentMax = array[0];
+    var max = array[0];
+    for (var i = 1; i < array.length; i += 1) {
+      currentMax = Math.max(array[i], currentMax + array[i]);
       max = Math.max(max, currentMax);
     }
     return max;