Add JavaScript and TypeScript code of permutations and n_queens (Chapter of Backtracking) (#494)

* Add JavaScript and TypeScript code of permutations and n_queens (Chapter of Backtracking)

* Update n_queens.js

* Update permutations_i.js

* Update permutations_ii.js

* Update n_queens.ts

* Update permutations_i.ts

* Update permutations_ii.ts

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Co-authored-by: Yudong Jin <krahets@163.com>

codes/javascript/chapter_backtracking/permutations_ii.js

@@ -0,0 +1,44 @@
+/**
+ * File: permutations_ii.js
+ * Created Time: 2023-05-13
+ * Author: Justin (xiefahit@gmail.com)
+ */
+
+/* 回溯算法：全排列 II */
+function backtrack(state, choices, selected, res) {
+    // 当状态长度等于元素数量时，记录解
+    if (state.length === choices.length) {
+        res.push([...state]);
+        return;
+    }
+    // 遍历所有选择
+    const duplicated = new Set();
+    choices.forEach((choice, i) => {
+        // 剪枝：不允许重复选择元素 且 不允许重复选择相等元素
+        if (!selected[i] && !duplicated.has(choice)) {
+            // 尝试：做出选择，更新状态
+            duplicated.add(choice); // 记录选择过的元素值
+            selected[i] = true;
+            state.push(choice);
+            // 进行下一轮选择
+            backtrack(state, choices, selected, res);
+            // 回退：撤销选择，恢复到之前的状态
+            selected[i] = false;
+            state.pop();
+        }
+    });
+}
+
+/* 全排列 II */
+function permutationsII(nums) {
+    const res = [];
+    backtrack([], nums, Array(nums.length).fill(false), res);
+    return res;
+}
+
+// Driver Code
+const nums = [1, 2, 2];
+const res = permutationsII(nums);
+
+console.log(`输入数组 nums = ${JSON.stringify(nums)}`);
+console.log(`所有排列 res = ${JSON.stringify(res)}`);