nozomi和字符串

用尺取法维护一个区间改变k个字符的区间

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>

using namespace std;

string s;
int n, k;

int deal(char a, char a1)// change a to a1
{
    int L = 0, R = 0, change = 0, ans = 1;
    for (int i = 0; i < n; i++){
        if (s[i] == a){
            if (change < k){
                change++;
                R++;
            }
            else{
                while (L <= R && s[L] != a) L++;
                L++;
                R++;
            }
        }
        else R++;
        ans = max(ans, R - L );
    }
    return ans;
}

int main(){
    while (cin >> n >> k){
        cin >> s;
        cout << max(deal('1', '0'), deal('0', '1')) << endl;
    }
}