docs: add _52_totalNQueens

Author: wangpeng

README.md

@@ -3,7 +3,7 @@
 [![996.icu](https://img.shields.io/badge/link-996.icu-red.svg)](https://996.icu)
 
 ## 说明
-- leetcode练习，坚持每天一道，目前已完成164道
+- leetcode练习，坚持每天一道，目前已完成165道
 - 解题语言是Java
 - 每道题都是可编译运行的
 - 每道题有自己的方法和他人优秀解法
@@ -21,7 +21,7 @@
 
 - [x]  [47. 全排列 II - Medium](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_47_permuteUnique.java)
 
-- [ ]  [52. N皇后 II - Hard](https://leetcode-cn.com/problems/n-queens-ii/)
+- [x]  [52. N皇后 II - Hard](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_52_totalNQueens.java)
 
 - [ ]  [77. 组合 - Medium](https://leetcode-cn.com/problems/combinations/)
 
@@ -58,7 +58,7 @@
 - [线段树](https://leetcode-cn.com/tag/segment-tree/)（9）
 - [二叉搜索树](https://leetcode-cn.com/tag/binary-search-tree/)（15）
 
-### 题目列表（更新中--已完成164）
+### 题目列表（更新中--已完成165）
 
 [Leetcode-Java(更多题解，持续更新)](https://github.com/pphdsny/Leetcode-Java)
 
@@ -112,6 +112,7 @@
 | #47   | [全排列 II](https://leetcode-cn.com/problems/permutations-ii/) | [PermuteUnique](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_47_permuteUnique.java) | [回溯算法](<https://leetcode-cn.com/tag/backtracking/>)      | Medium |                                                              |
 | #49   | [字母异位词分组](https://leetcode-cn.com/problems/group-anagrams/) | [GroupAnagrams](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_49_groupAnagrams.java) | [哈希表](<https://leetcode-cn.com/tag/hash-table/>)、[字符串](<https://leetcode-cn.com/tag/string/>) | Medium |                                                              |
 | #51   | [N皇后](https://leetcode-cn.com/problems/n-queens/)          | [SolveNQueens](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_51_solveNQueens_2.java) | [回溯算法](<https://leetcode-cn.com/tag/backtracking/>)      | Hard   | [自己原始解法](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_51_solveNQueens.java) |
+| #52   | [N皇后 II](https://leetcode-cn.com/problems/n-queens-ii/)    | [TotalNQueens](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_52_totalNQueens.java) | [回溯算法](<https://leetcode-cn.com/tag/backtracking/>)      | Hard   |                                                              |
 | #53   | [最大子序和](https://leetcode-cn.com/problems/maximum-subarray/) | [MaxSubArray.java](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_53_maxSubArray.java) | [数组](<https://leetcode-cn.com/tag/array/>)、[分治算法](<https://leetcode-cn.com/tag/divide-and-conquer/>)、[动态规划](<https://leetcode-cn.com/tag/dynamic-programming/>) | Easy   |                                                              |
 | #55   | [跳跃游戏](https://leetcode-cn.com/problems/jump-game/)      | [CanJump](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_55_canJump.java) | [贪心算法](https://leetcode-cn.com/tag/greedy/)、[数组](<https://leetcode-cn.com/tag/array/>) | Medium |                                                              |
 | #56   | [合并区间](https://leetcode-cn.com/problems/merge-intervals/) | [Merge](https://github.com/pphdsny/Leetcode-Java/blob/master/src/pp/arithmetic/leetcode/_56_merge.java) | [排序](https://leetcode-cn.com/tag/sort/)、[数组](<https://leetcode-cn.com/tag/array/>) | Medium |                                                              |