From c539d36bf7e666157667393c8ea4dc2480a27b9d Mon Sep 17 00:00:00 2001
From: zhaocchen <zhaocchen@163.com>
Date: Mon, 17 May 2021 23:41:31 +0800
Subject: [PATCH] feat: add javascript solution to lcci problem:
 No.1864.Minimum Number of Swaps to Make the Binary String Alternating

---
 .../README.md                                 | 33 +++++++++++++++++++
 .../README_EN.md                              | 33 +++++++++++++++++++
 .../Solution.js                               | 28 ++++++++++++++++
 3 files changed, 94 insertions(+)
 create mode 100644 solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/Solution.js

diff --git a/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/README.md b/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/README.md
index 0765c73638f03..3dc41a67d57d3 100644
--- a/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/README.md	
+++ b/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/README.md	
@@ -69,6 +69,39 @@
 
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {string} s
+ * @return {number}
+ */
+ var minSwaps = function(s) {
+    let n = s.length;
+    let n1 = [...s].reduce((a, c) => parseInt(c) + a, 0);
+    let n0 = n - n1;
+    let count = Infinity;
+    let half = n / 2;
+    // 101、1010
+    if (n1 == Math.ceil(half) && n0 == Math.floor(half)) {
+        let cur = 0;
+        for (let i = 0; i < n; i++) {
+            if (i % 2 == 0 && s.charAt(i) != '1') cur++;
+        }
+        count = Math.min(count, cur);
+    }
+    // 010、0101
+    if (n0 == Math.ceil(half) && n1 == Math.floor(half)) {
+        let cur = 0;
+        for (let i = 0; i < n; i++) {
+            if (i % 2 == 0 && s.charAt(i) != '0') cur++;
+        }
+        count = Math.min(count, cur);
+    }
+    return count == Infinity ? -1 : count;
+};
+```
+
 ### **...**
 
 ```
diff --git a/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/README_EN.md b/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/README_EN.md
index 86d4544d60727..b23a313f7e225 100644
--- a/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/README_EN.md	
+++ b/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/README_EN.md	
@@ -60,6 +60,39 @@ The string is now alternating.
 
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {string} s
+ * @return {number}
+ */
+ var minSwaps = function(s) {
+    let n = s.length;
+    let n1 = [...s].reduce((a, c) => parseInt(c) + a, 0);
+    let n0 = n - n1;
+    let count = Infinity;
+    let half = n / 2;
+    // 101、1010
+    if (n1 == Math.ceil(half) && n0 == Math.floor(half)) {
+        let cur = 0;
+        for (let i = 0; i < n; i++) {
+            if (i % 2 == 0 && s.charAt(i) != '1') cur++;
+        }
+        count = Math.min(count, cur);
+    }
+    // 010、0101
+    if (n0 == Math.ceil(half) && n1 == Math.floor(half)) {
+        let cur = 0;
+        for (let i = 0; i < n; i++) {
+            if (i % 2 == 0 && s.charAt(i) != '0') cur++;
+        }
+        count = Math.min(count, cur);
+    }
+    return count == Infinity ? -1 : count;
+};
+```
+
 ### **...**
 
 ```
diff --git a/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/Solution.js b/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/Solution.js
new file mode 100644
index 0000000000000..5ec0aee156a7c
--- /dev/null
+++ b/solution/1800-1899/1864.Minimum Number of Swaps to Make the Binary String Alternating/Solution.js	
@@ -0,0 +1,28 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+ var minSwaps = function(s) {
+    let n = s.length;
+    let n1 = [...s].reduce((a, c) => parseInt(c) + a, 0);
+    let n0 = n - n1;
+    let count = Infinity;
+    let half = n / 2;
+    // 101、1010
+    if (n1 == Math.ceil(half) && n0 == Math.floor(half)) {
+        let cur = 0;
+        for (let i = 0; i < n; i++) {
+            if (i % 2 == 0 && s.charAt(i) != '1') cur++;
+        }
+        count = Math.min(count, cur);
+    }
+    // 010、0101
+    if (n0 == Math.ceil(half) && n1 == Math.floor(half)) {
+        let cur = 0;
+        for (let i = 0; i < n; i++) {
+            if (i % 2 == 0 && s.charAt(i) != '0') cur++;
+        }
+        count = Math.min(count, cur);
+    }
+    return count == Infinity ? -1 : count;
+};
\ No newline at end of file