feat: add javascript solution to lcci problem: No.08.08.Permutation II (doocs#376)

Author: zhaocchen

lcci/08.08.Permutation II/README.md

@@ -48,6 +48,46 @@
 
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {string} S
+ * @return {string[]}
+ */
+var permutation = function(S) {
+    let res = [];
+    let arr = [...S];
+    arr.sort();
+    let prev = [];
+    let record = new Array(S.length).fill(false);
+    dfs(arr, 0, prev, record, res);
+    return res;
+};
+
+function dfs(arr, depth, prev, record, res) {
+    if (depth == arr.length) {
+        res.push(prev.join(''));
+        return;
+    }
+    for (let i = 0; i < arr.length; i++) {
+        if (record[i]) {
+            continue;
+        }
+        // 剪枝
+        if (i > 0 && arr[i] == arr[i - 1] && record[i - 1]) {
+            continue;
+        }
+        prev.push(arr[i]);
+        record[i] = true;
+        dfs(arr, depth + 1, prev, record, res);
+        // 回溯
+        prev.pop();
+        record[i] = false;
+    }
+}
+```
+
 ### **...**
 
 ```

lcci/08.08.Permutation II/README_EN.md

@@ -49,6 +49,46 @@
 
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {string} S
+ * @return {string[]}
+ */
+var permutation = function(S) {
+    let res = [];
+    let arr = [...S];
+    arr.sort();
+    let prev = [];
+    let record = new Array(S.length).fill(false);
+    dfs(arr, 0, prev, record, res);
+    return res;
+};
+
+function dfs(arr, depth, prev, record, res) {
+    if (depth == arr.length) {
+        res.push(prev.join(''));
+        return;
+    }
+    for (let i = 0; i < arr.length; i++) {
+        if (record[i]) {
+            continue;
+        }
+        // 剪枝
+        if (i > 0 && arr[i] == arr[i - 1] && record[i - 1]) {
+            continue;
+        }
+        prev.push(arr[i]);
+        record[i] = true;
+        dfs(arr, depth + 1, prev, record, res);
+        // 回溯
+        prev.pop();
+        record[i] = false;
+    }
+}
+```
+
 ### **...**
 
 ```

lcci/08.08.Permutation II/Solution.js

@@ -0,0 +1,35 @@
+/**
+ * @param {string} S
+ * @return {string[]}
+ */
+ var permutation = function(S) {
+    let res = [];
+    let arr = [...S];
+    arr.sort();
+    let prev = [];
+    let record = new Array(S.length).fill(false);
+    dfs(arr, 0, prev, record, res);
+    return res;
+};
+
+function dfs(arr, depth, prev, record, res) {
+    if (depth == arr.length) {
+        res.push(prev.join(''));
+        return;
+    }
+    for (let i = 0; i < arr.length; i++) {
+        if (record[i]) {
+            continue;
+        }
+        // 剪枝
+        if (i > 0 && arr[i] == arr[i - 1] && record[i - 1]) {
+            continue;
+        }
+        prev.push(arr[i]);
+        record[i] = true;
+        dfs(arr, depth + 1, prev, record, res);
+        // 回溯
+        prev.pop();
+        record[i] = false;
+    }
+}