Python题解 | #Sudoku#

def check(matrix, row, col, val):
    for i in range(9):
        if matrix[i][col] == val:
            return False
    for j in range(9):
        if matrix[row][j] == val:
            return False
    area_row = (row // 3) * 3
    area_col = (col // 3) * 3
    for x in range(area_row, area_row + 3):
        for y in range(area_col, area_col + 3):
            if matrix[x][y] == val:
                return False
    return True


def dfs(n):
    if n == 81:
        return True
    row = n // 9
    col = n % 9
    if matrix[row][col] != 0:
        return dfs(n + 1)
    else:
        for a in range(1, 10):
            if check(matrix, row, col, a):
                matrix[row][col] = a
                if dfs(n + 1):
                    return True
            matrix[row][col] = 0
        return False


while True:
    try:
        matrix = [[0] * 9 for _ in range(9)]
        for i in range(9):
            matrix[i] = list(map(int, input().strip().split()))
        dfs(0)
        for i in range(9):
            for j in range(8):
                print(matrix[i][j], end=' ')
            print(matrix[i][-1])
    except:
        break