Osajono

#include <iostream>
#include <string>
#include <string.h>
#include <stdio.h>
#include <algorithm>
//using namespace std;

unsigned int loweringSum(unsigned int i){
	//i>0
	if (i == 0){ return 0; }
	if (i == 1){ return 1; }
	return i + loweringSum(i - 1);
}

int main() {
	std::cin.sync_with_stdio(false);//Faster execution

	//char str[100001];
	std::string stro;
	//std::cin.getline(stro, 100001);//Gets the line entered and moves it to string
	std::cin >> stro;
	char* str = (char*)stro.c_str();
	unsigned int strLen = (unsigned)strlen(str);
	unsigned int osajonot = strLen;

	//Iteroi merkkijonoa
	/*for(unsigned int startIndex = 0; startIndex < (strLen - 1); startIndex++){//This takes too much time when going to 100k chars boundary
	//char atStart = str[startIndex];//s.at(startIndex);
	for(unsigned int i = startIndex + 1; i < strLen; i++){
	if(str[i] == str[startIndex]){
	osajonot++;
	}
	}
	}*/
	std::sort(str, str + strLen /*- 1*/);
	//std::string sorted(str);
	for (char c = 'A'; c <= 'Z'; c++){
		unsigned int lastIndexOf = stro.rfind(c) + 1;
		
		osajonot += loweringSum(lastIndexOf-1);// - sorted.find(c);
		
		stro.erase(0, lastIndexOf);
		if (!stro.length()){ break; }
	}
	std::cout << osajonot << std::endl;
	return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: TIME LIMIT EXCEEDED

Test 3

Group: 1

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 1

Verdict: TIME LIMIT EXCEEDED

Test 5

Group: 1

Verdict: TIME LIMIT EXCEEDED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 9

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 10

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED