Interesting Array

#include <bits/stdc++.h>

using namespace std;

const int NMAX = 1e5 + 5;
int N, a[NMAX];
long long ans = 1;

void solve(int st, int dr) {
    unordered_map<int,int> freq;
    for(int i = st; i <= dr; ++i)
        ++freq[a[i]];
    int fr_max = 1, fr_min = dr - st + 1;
    for(auto it : freq) {
        fr_max = max(fr_max, it.second);
        fr_min = min(fr_min, it.second);
    }
    ans = max(ans, 1LL * fr_max * fr_min);
    int last = 0;
    for(int i = st; i <= dr; ++i)
        if(freq[a[i]] == fr_min) {
            if(last) {
                solve(last, i - 1);
                last = 0;
            }
        }
        else
            if(last == 0)
                last = i;
    if(last)
        solve(last, dr);
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    cin >> N;
    for(int i = 1; i <= N; ++i)
        cin >> a[i];
    solve(1, N);
    cout << ans << '\n';
}