1907C - Removal of Unattractive Pairs - CodeForces Solution

#include <bits/stdc++.h>

using namespace std;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int t, n;
    string a;

    cin >> t;
    while (t)
    {
        array<int, 26> sum{};
        cin >> n >> a;
        for (auto i : a) ++sum[i-'a'];
        cout << max(n%2, n-2*(n-*max_element(sum.begin(), sum.end()))) << "\n";
        --t;
    }
}