[LeetCode]37. Sudoku Solver
来源:互联网 发布:vm虚拟机安装linux教程 编辑:程序博客网 时间:2024/06/14 20:24
Description
Write a program to solve a Sudoku puzzle by filling the empty cells.
Empty cells are indicated by the character ‘.’.
You may assume that there will be only one unique solution.
A sudoku puzzle…
…and its solution numbers marked in red.
Discussion
给出数独游戏的一个解。
这道题可以用回溯法解。与DFS方法类似,添加适当的剪枝。
对于当前某一个格子,将1-9代入,判断是否合法,如果合法,继续往下一个格子走,不合法则跳过。
判断是否合法可以仅对当前添加的格子进行判断,即判断它是否与同行,同列,同九宫格的数字相同,都不同则合法。
C++ Code
class Solution {public: void solveSudoku(vector<vector<char>>& board) { dfs(board, 0, 0); } bool dfs(vector<vector<char>> & board, int i, int j) { if(j >= 9) { return dfs(board, i + 1, 0); } if(i >= 9) { return true; } if(board[i][j] != '.') { return dfs(board, i, j + 1); } else { for(int k = 1; k <= 9; k++) { board[i][j] = (char)('0' + k); if(isValid(board, i, j)) { if(dfs(board, i, j + 1)) { return true; } } board[i][j] = '.'; } } return false; } bool isValid(vector<vector<char>> & board, int i, int j) { //判断board[i][j]是否与当前行的元素相同 for(int k = 0; k < 9; k++) { if(j != k && board[i][j] == board[i][k]) { return false; } } //判断board[i][j]是否与当前列的元素相同 for(int k = 0; k < 9; k++) { if(i != k && board[i][j] == board[k][j]) { return false; } } //判断board[i][j]是否与当前九宫格的元素相同,board[i/3*3][j/3*3]是board[i][j]所在九宫格的第一个元素 for(int row = i/3*3; row < i/3*3 + 3; row ++) { for(int col = j/3*3; col < j/3*3 + 3; col ++) { if(((i != row) || (j != col)) && board[i][j] == board[row][col]) { return false; } } } return true; }};
阅读全文
0 0
- LeetCode --- 37. Sudoku Solver
- LeetCode 37.Sudoku Solver
- [Leetcode] 37. Sudoku Solver
- [leetcode] 37. Sudoku Solver
- Leetcode 37. Sudoku Solver
- leetcode 37. Sudoku Solver
- LeetCode 37. Sudoku Solver
- leetcode.37. Sudoku Solver
- LeetCode-37.Sudoku Solver
- leetcode 37. Sudoku Solver
- (Leetcode)37. Sudoku Solver
- [LeetCode] 37. Sudoku Solver
- leetcode 37.Sudoku Solver
- leetcode 37. Sudoku Solver
- leetcode 37. Sudoku Solver
- leetcode-37. Sudoku Solver
- [LeetCode]37. Sudoku Solver
- leetcode 37. Sudoku Solver
- Cutterman插件安装及使用说明
- Ubuntu安装PhantomJS(不使用apt命令)
- 每天回顾linux命令(mkdir)
- IEDriverServer启动IE报错
- Maven 介绍(一)
- [LeetCode]37. Sudoku Solver
- Python 猜数字与模拟登陆
- 使用VMware安装linux怎么跳过简易模式安装
- 熊大UWB系列教程四:UWB超宽带三基站定位系统原理介绍与效果展示
- WEB-INF目录下的文件,访问WebContent下的静态文件
- Zygote进程启动过程源码分析
- Spring框架中自带的文件上传
- 【tomcat启动报错 】严重: Resource read error
- AndroidStudio自定义快捷键