feat: add js solution to lc problem: No.0137

Author: rain84

solution/0100-0199/0137.Single Number II/README.md

@@ -423,6 +423,21 @@ function singleNumber(nums: number[]): number {
 }
 ```
 
+#### JavaScript
+
+```ts
+function singleNumber(nums) {
+    let [ans, acc] = [0, 0];
+
+    for (const x of nums) {
+        ans ^= x & ~acc;
+        acc ^= x & ~ans;
+    }
+
+    return ans;
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/0100-0199/0137.Single Number II/README_EN.md

@@ -414,6 +414,21 @@ function singleNumber(nums: number[]): number {
 }
 ```
 
+#### JavaScript
+
+```ts
+function singleNumber(nums) {
+    let [ans, acc] = [0, 0];
+
+    for (const x of nums) {
+        ans ^= x & ~acc;
+        acc ^= x & ~ans;
+    }
+
+    return ans;
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/0100-0199/0137.Single Number II/Solution4.js

@@ -0,0 +1,10 @@
+function singleNumber(nums) {
+    let [ans, acc] = [0, 0];
+
+    for (const x of nums) {
+        ans ^= x & ~acc;
+        acc ^= x & ~ans;
+    }
+
+    return ans;
+}