Osajono

#include <bits/stdc++.h>

#define _ ios_base::sync_with_stdio(0);cin.tie();
#define mp make_pair
#define pb push_back

#define ll long long
#define pii pair<int,int>
#define vpii vector<pii>
#define vi vector<int>

#define EPS 2.220446e-02
#define PI 3.14159265358

using namespace std;

bool compare(const pii&a, const pii&b) {
    return a.first<b.first;
}

int main() { _ // OT2, n^2

    string s;
    cin >> s;

    int l = s.length();
    int sum = 0;
    for(int i=0;i<l;i++) {
        for(int j=i;j<l;j++) {
            if(s[i] == s[j]) {
                sum++;
            }
        }
    }

    cout << sum << endl;


    return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED