Osajono

#include <iostream>
#include <vector>
#include <map>
#include <string>

int main() {
	std::ios_base::sync_with_stdio(false);

	std::map<char, int> letters;

	std::string s;
	getline(std::cin, s);

	int l = s.length();
	char cur = ' ';

	std::map<char, int>::iterator itr;

	for (int i = 0; i < l; i++) {
		cur = s[i];

		itr = letters.find(cur);

		if (itr != letters.end()) {
			itr->second++;
		}
		else {
			letters.insert(std::pair<char, int>(cur, 1));
		}
		

	}

	int maara = 0;
	int curNum = 0;

	for (std::map<char, int>::iterator it = letters.begin(); it != letters.end(); it++) {
		curNum = it->second;
		maara += (curNum * (curNum + 1)) / 2;
	}

	std::cout << maara;

	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: 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