| 学习笔记 | |
| |#|Title|Solutions| | |
| |---|---|------| | |
| |208|[implement-trie-prefix-tree](https://leetcode-cn.com/problems/implement-trie-prefix-tree) | 前缀树([Go](../Week_07/208/implement_trie_prefix_tree.go),[Py](../Week_07/208/implement_trie_prefix_tree.py))| | |
| |212|[word-search-ii](https://leetcode-cn.com/problems/word-search-ii) | 前缀树+回溯([Go](../Week_07/212/word_search_ii.go),[Py](../Week_07/212/word_search_ii.py))| | |
| |547|[friend-circles](https://leetcode-cn.com/problems/friend-circles) | 深度优先([Go](../Week_07/547/friend_circles.go),[Py](../Week_07/547/friend_circles.py)),并查集([Go](../Week_07/547/friend_circles2.go),[Py](../Week_07/547/friend_circles2.py))| | |
| |130|[surrounded-regions](https://leetcode-cn.com/problems/surrounded-regions) | 深度优先([Go](../Week_07/130/surrounded_regions.go),[Py](../Week_07/130/surrounded_regions.py)),并查集([Go](../Week_07/130/surrounded_regions2.go))| | |
| |36|[valid-sudoku](https://leetcode-cn.com/problems/valid-sudoku) | 迭代([Go](../Week_07/36/valid_sudoku.go),[Py](../Week_07/36/valid_sudoku.py))| | |
| |37|[sudoku-solver](https://leetcode-cn.com/problems/sudoku-solver) | 回溯([Go](../Week_07/37/sudoku_solver.go),[Py](../Week_07/37/sudoku_solver.py))| | |
| |1091|[shortest-path-in-binary-matrix](https://leetcode-cn.com/problems/shortest-path-in-binary-matrix) | 广度优先搜索([Go](../Week_07/1091/shortest_path_in_binary_matrix.go),[Py](../Week_07/1091/shortest_path_in_binary_matrix.py))| | |
| |773|[sliding-puzzle](https://leetcode-cn.com/problems/sliding-puzzle) | 广度优先搜索([Go](../Week_07/773/sliding_puzzle.go),[Py](../Week_07/773/sliding_puzzle.py))| | |
| ## 题解 | |
| ### 208. implement-trie-prefix-tree | |
| 1. 哈希表：使用哈希表记录前缀关系，用一个标志记录是否是叶子节点 | |
| ### 212. word-search-ii | |
| 1. 前缀树+回溯 | |
| ### 547. friend-circles | |
| 1. 深度优先搜索 | |
| 2. 并查集 | |
| ### 130. surrounded-regions | |
| 1. 深度优先搜索: 从边界上为"O"的点深度优先搜索 | |
| 2. 并查集 | |
| ### 36. valid-sudoku | |
| 1. 迭代：使用三个9*9的数组记录每行、列、块是否合法，Golang可以使用`[9]uint16`压缩空间 | |
| ### 37. sudoku-solver | |
| 1. 回溯 | |
| ### 1091. shortest-path-in-binary-matrix | |
| 1. 广度优先搜索 | |
| ### 773. sliding-puzzle | |
| 1. 广度优先搜索: 使用一个字典记录每个index的邻居，后面就是每次移动`0` |