题解 | #Sudoku#

def getAbs(sudoku_sqr):
    all_num = set([i for i in range(1, 10)])
    line_abs = []
    for i in range(9):
        line_num = set(sudoku_sqr[i])-set([0])
        line_abs.append(all_num - line_num)

    col_abs = []
    for i in range(9):
        col_num = set([sudoku_sqr[j][i] for j in range(9)])-set([0])
        col_abs.append(all_num - col_num)

    win_abs = [[] for _ in range(3)]
    for i in range(3):
        for j in range(3):
            win_num = set([sudoku_sqr[i*3][j*3], sudoku_sqr[i*3][j*3+1], sudoku_sqr[i*3][j*3+2],
                           sudoku_sqr[i*3+1][j*3], sudoku_sqr[i*3+1][j*3+1], sudoku_sqr[i*3+1][j*3+2],
                           sudoku_sqr[i*3+2][j*3], sudoku_sqr[i*3+2][j*3+1], sudoku_sqr[i*3+2][j*3+2]]) - set([0])
            win_abs[i].append(all_num - win_num)

    ele_abs = [[None for __ in range(9)] for _ in range(9)]
    for i in range(9):
        for j in range(9):
            if not sudoku_sqr[i][j]:
                ele_abs[i][j] = line_abs[i]&col_abs[j]&win_abs[i//3][j//3]
    return ele_abs

def fillSqr(sudoku_sqr, absense):
    for k in range(1, 10):
        fillOcc = 0
        for i in range(9):
            for j in range(9):
                if absense[i][j] and len(absense[i][j]) == k:
                    fillment = list(absense[i][j])[0]
                    sudoku_sqr[i][j] = fillment
                    fillOcc = 1
                    break
            if fillOcc:
                break
        if fillOcc:
            break
    return sudoku_sqr

def finishedSudoku(sudoku_sqr):
    for i in range(9):
        for j in range(9):
            if not sudoku_sqr[i][j]:
                return False
    return True

in_sudoku_sqr = []
for _ in range(9):
    sudoku_line = list(map(int, input().split(' ')))
    in_sudoku_sqr.append(sudoku_line)

while not finishedSudoku(in_sudoku_sqr):
    abs_sqr = getAbs(in_sudoku_sqr)
    in_sudoku_sqr = fillSqr(in_sudoku_sqr, abs_sqr)

for i in range(9):
    for j in range(9):
        print(in_sudoku_sqr[i][j], end=' ')
    print('')

基本思路，统计每个空位的可能值，从可能值数量最小的开始填写，每次填写一个，就重新统计其他空位的可能值，直到所有空位填写完

统计每个空位的可能值时，不用暴力统计，只需要统计每行、每列、每个9宫格的可能值，然后在每一个元素上针对索引取并集