shudujuzhen/3

#include <stdio.h>
#include <stdbool.h>

#define SIZE 9

bool isValidSudoku(int matrix[SIZE][SIZE]);
void printMatrix(int matrix[SIZE][SIZE]);

int main() {
    int matrix[SIZE][SIZE] = {
        {5, 3, 0, 0, 7, 0, 0, 0, 0},
        {6, 0, 0, 1, 9, 5, 0, 0, 0},
        {0, 9, 8, 0, 0, 0, 0, 6, 0},
        {8, 0, 0, 0, 6, 0, 0, 0, 3},
        {4, 0, 0, 8, 0, 3, 0, 0, 1},
        {7, 0, 0, 0, 2, 0, 0, 0, 6},
        {0, 6, 0, 0, 0, 0, 2, 8, 0},
        {0, 0, 0, 4, 1, 9, 0, 0, 5},
        {0, 0, 0, 0, 8, 0, 0, 7, 9}
    };

    printf("The original Sudoku matrix: \n");
    printMatrix(matrix);

    if (isValidSudoku(matrix)) {
        printf("True: Valid initial Sudoku matrix!\n");
    } else {
        printf("False: Invalid initial Sudoku matrix!\n");
    }

    return 0;
}

bool isValidSudoku(int matrix[SIZE][SIZE]) {
    for (int i = 0; i < SIZE; i++) {
        for (int j = 0; j < SIZE; j++) {
            if (matrix[i][j] != 0) {
                for (int k = j + 1; k < SIZE; k++) {
                    if (matrix[i][k] == matrix[i][j] && matrix[i][k] != 0) {
                        printf("The number %d in the col %d has been used!\n", matrix[i][j], j + 1);
                        return false;
                    }
                }
                for (int k = i + 1; k < SIZE; k++) {
                    if (matrix[k][j] == matrix[i][j] && matrix[k][j] != 0) {
                        printf("The number %d in the row %d has been used!\n", matrix[i][j], i + 1);
                        return false;
                    }
                }
                // Check 3x3 block
                int blockRow = i - i % 3;
                int blockCol = j - j % 3;
                for (int p = 0; p < 3; p++) {
                    for (int q = 0; q < 3; q++) {
                        if (matrix[blockRow + p][blockCol + q] == matrix[i][j] &&
                            matrix[blockRow + p][blockCol + q] != 0 &&
                            (blockRow + p != i || blockCol + q != j)) {
                            printf("The number %d in the block %d has been used!\n", matrix[i][j], (i / 3) * 3 + j / 3 + 1);
                            return false;
                        }
                    }
                }
            }
        }
    }
    return true;
}

void printMatrix(int matrix[SIZE][SIZE]) {
    for (int i = 0; i < SIZE; i++) {
        for (int j = 0; j < SIZE; j++) {
            printf("%c ", matrix[i][j] != 0 ? '1' + matrix[i][j] - 1 : '.');
            if (j % 3 == 2 && j != SIZE - 1) printf("| ");
        }
        if (i % 3 == 2 && i != SIZE - 1) printf("\n---------------------\n");
        else if (i != SIZE - 1) printf("\n");
    }
}