hdu6103[尺取法] 2017多校6

/*hdu6103[尺取法] 2017多校6*/
#include <bits/stdc++.h>
using namespace std;
int T, m;
char str[];
void solve() {
    int ans = ;
    int n = strlen(str);
    for (int i = ; i < n; i++) {
        int l = , r = , p1 = i, p2 = i + , cost = ;
        while (p1 - r >=  && p2 + r < n) {
            if (cost + abs(str[p1 - r] - str[p2 + r]) <= m) {
                cost += abs(str[p1 - r] - str[p2 + r]);
                ans = max(++r - l, ans);
            }
            else {
                cost -= abs(str[p1 - l] - str[p2 + l]);
                l++;
            }

        }
        l = r = cost = , p1 = i - , p2 = i + ;
        while (p1 - r >=  && p2 + r < n) {
            if (cost + abs(str[p1 - r] - str[p2 + r]) <= m) {
                cost += abs(str[p1 - r] - str[p2 + r]);
                ans = max(++r - l, ans);
            }
            else {
                cost -= abs(str[p1 - l] - str[p2 + l]);
                l++;
            }
        }
    }
    printf("%d\n", ans);
}
int main() {
    scanf("%d", &T);
    while (T--) {
        scanf("%d%s", &m, str);
        solve();
    }
    return ;
}