hdu6103[尺取法] 2017多校6

Posted 2020-10-02

/*hdu6103[尺取法] 2017多校6*/
#include <bits/stdc++.h>
using namespace std;
int T, m;
char str[20005];
void solve() {
    int ans = 0;
    int n = strlen(str);
    for (int i = 0; i < n; i++) {
        int l = 0, r = 0, p1 = i, p2 = i + 1, cost = 0;
        while (p1 - r >= 0 && 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 = 0, p1 = i - 1, p2 = i + 1;
        while (p1 - r >= 0 && 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 0;
}