feat: add javascript solution to lc problem: No.0046.Permutations (doocs#415)

Author: zhaocchen

solution/0000-0099/0046.Permutations/README.md

@@ -138,6 +138,38 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} nums
+ * @return {number[][]}
+ */
+var permute = function(nums) {
+    let res = [];
+    let solution = [];
+    let record = new Array(nums.length).fill(false);
+    dfs(nums, 0, record, solution, res);
+    return res;
+};
+
+function dfs (nums, depth, record, solution, res) {
+    if (depth == nums.length) {
+        res.push(solution.slice());
+        return;
+    }
+    for (let i = 0; i < nums.length; i++) {
+        if (!record[i]) {
+            solution.push(nums[i]);
+            record[i] = true;
+            dfs(nums, depth + 1, record, solution, res);
+            solution.pop();
+            record[i] = false;
+        }
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0000-0099/0046.Permutations/README_EN.md

@@ -112,6 +112,38 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} nums
+ * @return {number[][]}
+ */
+var permute = function(nums) {
+    let res = [];
+    let solution = [];
+    let record = new Array(nums.length).fill(false);
+    dfs(nums, 0, record, solution, res);
+    return res;
+};
+
+function dfs (nums, depth, record, solution, res) {
+    if (depth == nums.length) {
+        res.push(solution.slice());
+        return;
+    }
+    for (let i = 0; i < nums.length; i++) {
+        if (!record[i]) {
+            solution.push(nums[i]);
+            record[i] = true;
+            dfs(nums, depth + 1, record, solution, res);
+            solution.pop();
+            record[i] = false;
+        }
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0000-0099/0046.Permutations/Solution.js

@@ -0,0 +1,27 @@
+/**
+ * @param {number[]} nums
+ * @return {number[][]}
+ */
+ var permute = function(nums) {
+    let res = [];
+    let solution = [];
+    let record = new Array(nums.length).fill(false);
+    dfs(nums, 0, record, solution, res);
+    return res;
+};
+
+function dfs (nums, depth, record, solution, res) {
+    if (depth == nums.length) {
+        res.push(solution.slice());
+        return;
+    }
+    for (let i = 0; i < nums.length; i++) {
+        if (!record[i]) {
+            solution.push(nums[i]);
+            record[i] = true;
+            dfs(nums, depth + 1, record, solution, res);
+            solution.pop();
+            record[i] = false;
+        }
+    }
+}