Osajono

import java.util.Scanner;
public class Test {
    public static void main(String[] args) {
        Scanner inp = new Scanner(System.in);
        String test = inp.nextLine();
        long[] num;
        num = new long[26];
        char[] testa = test.toCharArray();
        for(char t : testa){
            int cnum = (int) t;
            int ccnum = cnum - 65;
            num[ccnum] = num[ccnum] + 1;            
        }
        long ans = 0;
        for(long n : num){
            ans = ans + ((n * (n + 1))/2);
        }
        System.out.println(ans);
        
        
        }
    }

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