LeetCode037 Sudoku Solver

详细见：leetcode.com/problems/sudoku-solver

Java Solution: github

package leetcode;/* * 解数独 * 方法应该是试凑和回溯 */public class P037_SudokuSolver {public static void main(String[] args) {}/* * 还有很多bug */static class Solution {private boolean[][] isValidRow = new boolean[9][9];private boolean[][] isValidColumn = new boolean[9][9];private boolean[][] isValidNine = new boolean[9][9];private boolean isSuccess = false;public void solveSudoku(char[][] board) {for (int i = 0; i < 9; i++)for (int j = 0; j < 9; j++)if (board[i][j] != '.')init(board, i, j);solve(board, 0, 0);}private void solve(char[][] board, int i, int j) {if (true == isSuccess)return;if (i > 8) {isSuccess = true;return;}if (board[i][j] != '.') {if (j < 8)solve(board, i, j + 1);elsesolve(board, i + 1, 0);if (isSuccess)return;} else {int temp = i / 3 * 3 + j / 3;for (int n = 0; n < 9; n++) {if (!isValidColumn[j][n] && !isValidRow[i][n] && !isValidNine[temp][n]) {board[i][j] = (char) (n + '1');isValidColumn[j][n] = isValidRow[i][n] = isValidNine[temp][n] = true;if (j < 8)solve(board, i, j + 1);elsesolve(board, i + 1, 0);isValidColumn[j][n] = isValidRow[i][n] = isValidNine[temp][n] = false;if (isSuccess)return;}}}}private void init(char[][] board, int i, int j) {isValidRow[i][board[i][j] - '1'] = true;isValidColumn[j][board[i][j] - '1'] = true;isValidNine[i / 3 * 3 + j / 3][board[i][j] - '1'] = true;}}/* * 36 ms * 18.91% */static class Solution2 {public void solveSudoku(char[][] board) {solveSudoku2(board);}public boolean solveSudoku2(char[][] board) {for (int i = 0; i < 9; ++i)for (int j = 0; j < 9; ++j) {if (board[i][j] == '.') {for (int k = 0; k < 9; ++k) {board[i][j] = (char) ('1' + k);if (isValid(board, i, j) && solveSudoku2(board))return true;board[i][j] = '.';}return false;}}return true;}private boolean isValid(char[][] board, int x, int y) {int i, j;for (i = 0; i < 9; i++)if (i != x && board[i][y] == board[x][y])return false;for (j = 0; j < 9; j++)if (j != y && board[x][j] == board[x][y])return false;for (i = 3 * (x / 3); i < 3 * (x / 3 + 1); i++)for (j = 3 * (y / 3); j < 3 * (y / 3 + 1); j++)if ((i != x || j != y) && board[i][j] == board[x][y])return false;return true;}}}

C Solution: github

/*    url: leetcode.com/problems/sudoku-solver/    19ms 11.43%*/#include <stdio.h>#include <stdlib.h>#define bool intint isValid(char** b, int x, int y) {int i = 0, j = 0, k = 0;    for (k = 0; k < 9; k ++) {        if (k != x && b[k][y] == b[x][y])return 0;        if (k != y && b[x][k] == b[x][y])return 0;        i = (x / 3) * 3 + k / 3;        j = (y / 3) * 3 + k % 3;        if ((i != x || j != y) && b[i][j] == b[x][y])            return 0;    }return 1;}bool solveSudoku2(char** b) {    int i = 0, j = 0, k = 0;for (i = 0; i < 9; ++i)for (j = 0; j < 9; ++j) {if (b[i][j] != '.') continue;for (k = 0; k < 9; ++k) {b[i][j] = (char) ('1' + k);if (isValid(b, i, j) && solveSudoku2(b))return 1;b[i][j] = '.';}return 0;}return 1;}void solveSudoku(char** b, int rs, int cs) {    int val = solveSudoku2(b);    printf("answer is %d\r\n", val);}char* setChar(char* src, int n) {    int i = 0;    char* dst = (char*)malloc(sizeof(char) * (n + 1));    for (i = 0; i <= n; i ++)        *(dst + i) = *(src + i);    return dst;}int main() {    char** b = (char **) malloc(sizeof(char *) * 9);    char* t = NULL, * tt = NULL;    int rs = 9, cs = 9, i = 0, j = 0;    b[0] = setChar("..9748...", 9);    b[1] = setChar("7........", 9);    b[2] = setChar(".2.1.9...", 9);    b[3] = setChar("..7...24.", 9);    b[4] = setChar(".64.1.59.", 9);    b[5] = setChar(".98...3..", 9);    b[6] = setChar("...8.3.2.", 9);    b[7] = setChar("........6", 9);    b[8] = setChar("...2759..", 9);    solveSudoku(b, rs, cs);    for (i = 0; i < 9; i ++) {        for (j = 0; j < 9; j ++) {            printf("%c ", b[i][j]);        }        printf("\r\n");    }    for (i = 0; i < 9; i ++)        free(*(b + i));    free(b);    return 0;}

Python Solution: github

#coding=utf-8'''    url: leetcode.com/problems/sudoku-solver/    @author:     zxwtry    @email:      [e-mail]    @date:       2017年4月5日    @details:    Solution: 1709ms 12.51%'''from jinja2._compat import unichrclass Solution(object):    def isValid(self, b, x, y):        x_base, y_base = (x // 3) * 3, (y // 3) * 3        for k in range(9):            if x != k and b[x][y]==b[k][y]:                return False            if y != k and b[x][y]==b[x][k]:                return False            new_x, new_y = x_base+(k // 3), y_base+(k % 3)            if new_x != x and new_y != y and b[x][y] == b[new_x][new_y]:                return False        return True        def solve(self, b):        for x in range(9):            for y in range(9):                if b[x][y] != '.':continue                for k in range(9):                    b[x][y]=unichr(ord('1')+k)                    if self.isValid(b, x, y)\                    and self.solve(b):                        return True                    b[x][y] = '.'                return False        return True        def solveSudoku(self, b):        """        :type b: List[List[str]]        :rtype: void Do not return anything, modify b in-place instead.        """        self.solve(b)if __name__ == "__main__":    b=[list("..9748..."),\       list("7........"),\       list(".2.1.9..."),\       list("..7...24."),\       list(".64.1.59."),\       list(".98...3.."),\       list("...8.3.2."),\       list("........6"),\       list("...2759..")]    Solution().solve(b)    print(b)