添加题46，47

Author: ligecarryme

算法思维/回溯法.md

@@ -68,4 +68,82 @@ function helper(i: number, nums: number[], res: number[][], tmp: number[]): void
 
 ##### [46. 全排列](https://leetcode-cn.com/problems/permutations/)
 
-给定一个不含重复数字的数组 `nums` ，返回其 **所有可能的全排列** 。你可以 **按任意顺序** 返回答案。
+给定一个不含重复数字的数组 `nums` ，返回其 **所有可能的全排列** 。你可以 **按任意顺序** 返回答案。
+
+```tsx
+function permute(nums:number[]):number[][]{
+const res:number[][] = []
+const templist:number[] = []
+const visited:boolean[] =newArray(nums.length).fill(false)
+backTrack(nums, res, templist, visited)
+returnres
+};
+
+function backTrack(nums, res, templist, visited){
+if (templist.length===nums.length){
+res.push([].concat(templist))
+return
+ }
+for (let i =0; i<nums.length; i++){
+if (visited[i]){
+continue
+ }
+templist.push(nums[i])
+visited[i] =true
+backTrack(nums, res, templist, visited)
+visited[i] =false
+templist.pop(nums[i])
+ }
+}
+```
+
+##### [47. 全排列 II](https://leetcode-cn.com/problems/permutations-ii/)
+
+给定一个可包含重复数字的序列 `nums` ，**按任意顺序** 返回所有不重复的全排列。
+
+```tsx
+function permuteUnique(nums:number[]):number[][]{
+nums=nums.sort((a, b) =>a-b)
+const res:number[][] = []
+const templist:number[] = []
+const visited:boolean[] =newArray(nums.length).fill(false)
+backTrack(nums, res, templist, visited)
+returnres
+};
+
+function backTrack(nums, res, templist, visited){
+if (templist.length===nums.length){
+res.push([].concat(templist))
+return
+ }
+for (let i =0; i<nums.length; i++){
+if (visited[i]){
+continue
+ }
+if (i>0&&nums[i] ===nums[i-1] &&!visited[i-1]){
+continue
+ }
+templist.push(nums[i])
+visited[i] =true
+backTrack(nums, res, templist, visited)
+visited[i] =false
+templist.pop(nums[i])
+ }
+}
+```
+
+## 练习
+
+-[subsets](https://leetcode-cn.com/problems/subsets/)
+-[subsets-ii](https://leetcode-cn.com/problems/subsets-ii/)
+-[permutations](https://leetcode-cn.com/problems/permutations/)
+-[permutations-ii](https://leetcode-cn.com/problems/permutations-ii/)
+
+挑战题目
+
+-[combination-sum](https://leetcode-cn.com/problems/combination-sum/)
+-[letter-combinations-of-a-phone-number](https://leetcode-cn.com/problems/letter-combinations-of-a-phone-number/)
+-[palindrome-partitioning](https://leetcode-cn.com/problems/palindrome-partitioning/)
+-[restore-ip-addresses](https://leetcode-cn.com/problems/restore-ip-addresses/)
+-[permutations](https://leetcode-cn.com/problems/permutations/)
+