题解 | 小红的矩阵染色

贪心算法，计算最长列连续的o字符长度，计数，然后一个一个减下去。

n, m, k = map(int, input().split())

matrix = []
for _ in range(n):
    tmp = []
    for each in input():
        tmp.append(each)
    matrix.append(tmp)

# 求最长连续0的长度
nums = [0] * (n+1)
for x in range(m):
    counter = 0
    for i in range(n):
        if matrix[i][x] == "o":
            counter += 1
        else:
            nums[counter] += 1
            counter = 0
    if matrix[-1][x] == "o":
        nums[counter] += 1

def fun(nums, k):
    result = 0
    for i in range(n, 0, -1):
        if nums[i] == 0:
            continue
        while nums[i] > 0:
            if k <= i:
                result = result + k - 1
                return result
            else:
                result = result + i - 1
                k = k - i
                nums[i] -= 1
    return result
print(fun(nums, k))