问题描述

求 $\{s_n\}(s_i \in [\texttt{o},\texttt{p}])$ 中最长的所有出现的字符的数量相等的子串长度。

35pts 代码

不知道为啥错。

#include <bits/stdc++.h>
using namespace std;
long long n, maxx = -0x3f3f3f3f;
long long a[200010], sum[200010];
char c;
map<int, long long> Mp;

int main() {
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> c;
        if (c == 'l') a[i] = 1;
        else if (c == 'r') a[i] = -1;
    }
    for (int i = 1; i <= n + 1; i++) {
        sum[i + 1] = sum[i] + a[i];
    }
    for (int i = 1; i <= n + 1; i++) {
        if (Mp[sum[i]]) maxx = max(maxx, i - Mp[sum[i]]);
        else Mp[sum[i]] = i;
    }
    cout << maxx;
    return 0;
}