Osajono

import java.util.Arrays;

public class Osis3 {
	public static void main(String[] args) {
		IO oi = new IO();
		
		String str = oi.next();
		char[] arr = str.toCharArray();
		Arrays.sort(arr);
		long len = arr.length;
		long[] counts = new long[26];
		
		long result = 0;
		
		for(int i = 0; i < len; i++)
			counts[arr[i]-65]++;
		
		for(int i = 0; i < counts.length; i++)
			result += counts[i] * (counts[i] + 1) / 2;
		
		oi.println(result);
		oi.close();
	}
}

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: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED