Osajono

#include <iostream>

int main() {
	char j[100000];
	std::cin >> j;
	int n = 100000;
	int chars[26] = {0};
	for (int i = 0; i < 100000; i++) {
		if (int(j[i]) == 0) {
			n = i;
			i = 100002;
			continue;
		}
		chars[int(j[i]) - 65]++;
	}
	int ans = n;
	for (int i = 0; i < 26; i++) {
		int cn = chars[i];
		if (cn > 3) {
			ans += ((cn - 3)*((cn - 3) + 1)) / 2 + cn - 3 + cn;
		}
		else if (cn > 0) {
			if (cn == 2) ans++;
			else if (cn == 3) ans += 3;
		}
	}
	std::cout << ans << "\n";
}

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: WRONG ANSWER

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: WRONG ANSWER

Test 14

Group: 3

Verdict: WRONG ANSWER

Test 15

Group: 3

Verdict: WRONG ANSWER