题目

编写一个程序，通过填充空格来解决数独问题。

数独的解法需 遵循如下规则：

1. 数字 1-9 在每一行只能出现一次。
2. 数字 1-9 在每一列只能出现一次。
3. 数字 1-9 在每一个以粗实线分隔的 3x3 宫内只能出现一次。（请参考示例图）

数独部分空格内已填入了数字，空白格用 '.' 表示。

示例 1：

输入：board = [["5","3",".",".","7",".",".",".","."],["6",".",".","1","9","5",".",".","."],[".","9","8",".",".",".",".","6","."],["8",".",".",".","6",".",".",".","3"],["4",".",".","8",".","3",".",".","1"],["7",".",".",".","2",".",".",".","6"],[".","6",".",".",".",".","2","8","."],[".",".",".","4","1","9",".",".","5"],[".",".",".",".","8",".",".","7","9"]]
输出：[["5","3","4","6","7","8","9","1","2"],["6","7","2","1","9","5","3","4","8"],["1","9","8","3","4","2","5","6","7"],["8","5","9","7","6","1","4","2","3"],["4","2","6","8","5","3","7","9","1"],["7","1","3","9","2","4","8","5","6"],["9","6","1","5","3","7","2","8","4"],["2","8","7","4","1","9","6","3","5"],["3","4","5","2","8","6","1","7","9"]]
解释：输入的数独如上图所示，唯一有效的解决方案如下所示：

提示：

• board.length == 9
• board[i].length == 9
• board[i][j] 是一位数字或者 '.'
• 题目数据 保证 输入数独仅有一个解

代码

可以参考前身：有效的数独

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>void solveSudoku(char **board, int boardSize, int *boardColSize);
bool isValidSudoku(char **board, int boardSize, int *boardColSize);int main()
{// char b[9][10] = //     {"53..7....",//      "6..195...",//      ".98....6.",//      "8...6...3",//      "4..8.3..1",//      "7...2...6",//      ".6....28.",//      "...419..5",//      "....8..79"};char b[9][10]={"..9748...","7........",".2.1.9...","..7...24.",".64.1.59.",".98...3..","...8.3.2.","........6","...2759.."};int t, *te;char **board = (char **)malloc(sizeof(char *) * 9);for (int i = 0; i < 9; i++){board[i] = b[i];printf("%s ", b[i]);}printf("\n");solveSudoku(board, t, te);for (int i = 0; i < 9; i++){printf("%s ", board[i]);}return 0;
}void solveSudoku(char **board, int boardSize, int *boardColSize)
{int r, c;for (int p = 0; p < 9; p++){for (int q = 0; q < 9; q++){if (board[p][q] == '.'){r = p;c = q;continue;}}}static int sign = 0;for (int i = 0; i < 9; i++){for (int j = 0; j < 9; j++){if (board[i][j] == '.'){int p;for (p = 1; p <= 9 && sign == 0; p++){board[i][j] = p + '0';if (isValidSudoku(board, boardSize, boardColSize) == 1){if (i == r && j == c){sign = 1;}solveSudoku(board, boardSize, boardColSize);if (sign == 1){return;}}else{sign = 0;continue;}}if (p == 10){board[i][j] = '.';}return;}}}for (int i = 0; i < 9; i++){printf("%s ", board[i]);}printf("\n");
}bool isValidSudoku(char **board, int boardSize, int *boardColSize)
{int rownums[10], colnums[10];memset(rownums, 0, sizeof(rownums));memset(colnums, 0, sizeof(colnums));for (int i = 0; i < 9; i++){for (int j = 0; j < 9; j++){if (board[i][j] != '.'){int number = board[i][j] - '0';if (rownums[number] == 0){rownums[number] = 1;}elsereturn false;}if (board[j][i] != '.'){int number = board[j][i] - '0';if (colnums[number] == 0){colnums[number] = 1;}elsereturn false;}}memset(rownums, 0, sizeof(rownums));memset(colnums, 0, sizeof(colnums));}int i = 0, j = 0;for (int p = 3; p <= 9; p = p + 3){for (int q = 3; q <= 9; q = q + 3){i = p - 3;for (; i < p; i++){j = q - 3;for (; j < q; j++){if (board[i][j] != '.'){int number = board[i][j] - '0';if (rownums[number] == 0){rownums[number] = 1;}elsereturn false;}}}memset(rownums, 0, sizeof(rownums));}}return true;
}