# 2379. Minimum Recolors to Get K Consecutive Black Blocks
###### tags: `Leetcode` `Easy` `Sliding Window`
Link: https://leetcode.com/problems/minimum-recolors-to-get-k-consecutive-black-blocks/description/
## 思路
fixed length sliding window
## Code

class Solution {
    public int minimumRecolors(String blocks, int k) {
        int cnt = 0, ans = Integer.MAX_VALUE;
        for(int i=0; i<blocks.length(); i++){
            if(blocks.charAt(i)=='W') cnt++;
            if(i>=k-1){
                if(i>=k && blocks.charAt(i-k)=='W') cnt--;
                ans = Math.min(ans, cnt);
            }
        }
        return ans;
    }
}