题目描述

题解思路

本题可以转换为求长度为k的子数组中白色块的最少数量

我们遍历长度为k的窗口，我们只需要记录窗口内的白色块的数量即可，遍历过程中刷新白色块的数量的最小值

题解代码

impl Solution {
    pub fn minimum_recolors(blocks: String, k: i32) -> i32 {
        let blocks = blocks.as_bytes();

        let mut sum = 0;

        for i in 0..k as usize {
            if blocks[i] == b'W' {
                sum += 1;
            }
        }

        let mut min_sum = sum;

        for i in k as usize..blocks.len() {
            if blocks[i] == b'W' {
                sum += 1;
            }

            if blocks[i-k as usize] == b'W' {
                sum -= 1;
            }

            min_sum = min_sum.min(sum);
        }

        min_sum
    }
}

题目链接

https://leetcode.cn/problems/minimum-recolors-to-get-k-consecutive-black-blocks/