nailongnailong/3.cpp

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

bool panduan(int board[9][9]) {
    for (int i = 0; i < 9; i++) {
        bool row[10] = { 0 }, col[10] = { 0 }, block[10] = { 0 }; 
        for (int j = 0; j < 9; j++) {
            if (board[i][j] != 0) {
                if (row[board[i][j]]) {
                    printf("The number %d in row %d has been used!\n", board[i][j], i);
                    return false;
                }
                row[board[i][j]] = true;
            }
           
            if (board[j][i] != 0) {
                if (col[board[j][i]]) {
                    printf("The number %d in column %d has been used!\n", board[j][i], i);
                    return false;
                }
                col[board[j][i]] = true;
            }
            
            int blockRow = 3 * (i / 3), blockCol = 3 * (i % 3);
            if (board[blockRow + j / 3][blockCol + j % 3] != 0) {
                if (block[board[blockRow + j / 3][blockCol + j % 3]]) {
                    printf("The number %d in block %d has been used!\n",
                        board[blockRow + j / 3][blockCol + j % 3], (i / 3) * 3 + (i % 3));
                    return false;
                }
                block[board[blockRow + j / 3][blockCol + j % 3]] = true;
            }
        }
    }
    return true;
}