题解 | #Sudoku#

table = []
for _ in range(9):
    table.append(input().split())


def isvalid(r, c, num) -> bool:
    for i in range(9):
        if table[r][i] == str(num) or table[i][c] == str(num):
            return False

    for i in range(3):
        for j in range(3):
            if table[r // 3 * 3 + i][c // 3 * 3 + j] == str(num):
                return False
    return True


def solved() -> bool:
    for r in range(9):
        for c in range(9):
            if table[r][c] == "0":
                for num in range(1, 10):
                    if isvalid(r, c, num):
                        table[r][c] = str(num)
                        if solved():
                            return True
                        table[r][c] = "0"
                return False
    return True


solved()
for row in table:
    print(" ".join(row))