import random
import numpy as np


# 获取格子所在的行的全部格子
def get_row(sudo, row):
    return sudo[row, :]


# 获取格子所在的列的全部格子
def get_col(sudo, col):
    return sudo[:, col]


# 获取格子所在的九宫格的全部格子
def get_block(sudo, row, col):
    row_start = row // 3 * 3
    col_start = col // 3 * 3
    return sudo[row_start: row_start + 3, col_start: col_start + 3]


# 打印数独
def print_sudo(sudo):
    for row_index, row in enumerate(sudo):
        if row_index % 3 == 0 and row_index != 0:
            print('-' * (9 + 8 + 4))
        row = list(map(str, row.tolist()))
        row.insert(6, '|')
        row.insert(3, '|')
        row_str = ' '.join(row)
        print(row_str.replace('0', ' '))

def create_base_sudo():
    # 9*9的二维矩阵，每个格子默认值为0
    sudo = np.zeros((9, 9), dtype=int)
    # 随机生成起始的基数(1 ~ 9)
    num = random.randrange(9) + 1

    # 遍历从左到右，从上到下逐个遍历
    for row_index in range(9):
        for col_index in range(9):
            # 获取该格子对应的行、列、九宫格
            sudo_row = get_row(sudo, row_index)
            sudo_col = get_col(sudo, col_index)
            sudo_block = get_block(sudo, row_index, col_index)

            # 如果该数字已经存在于对应的行、列、九宫格
            # 则继续判断下一个候选数字，直到没有重复
            while num in sudo_row or num in sudo_col or num in sudo_block:
                num = num % 9 + 1

            # 赋值
            sudo[row_index, col_index] = num
            num = num % 9 + 1
    return sudo


def random_sudo(sudo, times):
    for _ in range(times):
        # 随机交换两行
        rand_row_base = random.randrange(3) * 3  # 从0，3，6 随机取一个
        rand_rows = random.sample(range(3), 2)  # 从 0，1，2中随机取两个数
        row_1 = rand_row_base + rand_rows[0]
        row_2 = rand_row_base + rand_rows[1]
        sudo[[row_1, row_2], :] = sudo[[row_2, row_1], :]

        # 随机交换两列
        rand_col_base = random.randrange(3) * 3
        rand_cols = random.sample(range(3), 2)
        col_1 = rand_col_base + rand_cols[0]
        col_2 = rand_col_base + rand_cols[1]
        sudo[:, [col_1, col_2]] = sudo[:, [col_2, col_1]]


def get_sudo_subject(sudo, del_nums):
    subject = sudo.copy()

    # 随机擦除（从0到80，随机取要删除的个数）
    clears = random.sample(range(81), del_nums)
    for clear_index in clears:
        # 把0到80的坐标转化成行和列索引
        # 这样就不会重复删除同一个格子的数字
        row_index = clear_index // 9
        col_index = clear_index % 9
        subject[row_index, col_index] = 0
    return subject


if __name__ == '__main__':
    max_clear_count = 64  # 最多清除个数
    min_clear_count = 14  # 最少清除个数

    # 设置难度等级，1~5，5个等级：入门、初级、熟练、精通、大神
    level = 3

    # 每个等级的个数
    each_level_count = (max_clear_count - min_clear_count) / 5

    # 该等级最小数
    level_start = min_clear_count + (level - 1) * each_level_count
    # 该等级范围内的随机数
    del_nums = random.randrange(level_start, level_start + each_level_count)

    # 生成基本盘
    sudo = create_base_sudo()
    # 生成终盘
    random_sudo(sudo, 50)
    # 获取数独题目
    subject = get_sudo_subject(sudo, del_nums)

    print('题目：')
    print('=' * 26)
    print_sudo(subject)
    print('\n答案：')
    print('=' * 26)
    print_sudo(sudo)