minerobots

def min_mine_robots(n, nums):

    def compute_right_mat():
        nonlocal mat, right_mat
        for r in range(n):
            rs = 0
            for c in range(n-1, -1, -1):
                if mat[r][c]:
                    rs += 1
                right_mat[r][c] = rs

    def compute_up_mat():
        nonlocal mat, up_mat
        for c in range(n):
            rs = 0
            for r in range(n):
                if mat[r][c]:
                    rs += 1
                up_mat[r][c] = rs

    mat = [[False for c in range(n)] for r in range(n)]
    for num in nums:
        r = n - 1 - num // n
        c = num % n
        mat[r][c] = True

    up_mat = [[0 for c in range(n)] for r in range(n)]
    right_mat = [[0 for c in range(n)] for r in range(n)]

    mines_left = len(nums)
    result = 0
    while mines_left > 0:
        compute_up_mat()
        compute_right_mat()
        x = 0
        y = n - 1
        result += 1

        while x < n and y >= 0:
            if mat[y][x]:
                mat[y][x] = False
                mines_left -= 1
                if mines_left == 0:
                    break
            if x < n-1 and right_mat[y][x+1] > 0:
                x += 1
            elif y > 0 and up_mat[y-1][x] > 0:
                y -= 1
                if y < 0:
                    pass
            else:
                break
    return result