B_Erase_First_or_Second_Letter.cpp

#include<bits/stdc++.h>
using namespace std ; 

# define int long long int 
# define vi vector<int> 
# define vs vector<string> 
# define vv vector<vector<int>>
# define f(i,a,b) for(int i=a;i<b;i++)
# define in cin>>
# define out cout<<
# define nl <<endl;
# define input(arr) fr(0,arr.size()) in arr[i] 
# define output(arr) fr(0,arr.size()) out arr[i]<<' ' 
# define mod 1e9+7
# define ps(x,y) fixed<<setprecision(y)<<x
# define setbits(x) __builtin_popcountll(x)
# define zrobits(x) __builtin_ctzll(x)
# define inf 1e18
# define sortv(a) sort(a.begin(),a.end())
                                        
int gcd(int a, int b){return b == 0 ? a : gcd(b, a % b);}
bool isprime(int x){for(int i=2;i*i<=x;i++) if(x%i==0) return 0 ;return (x==1? 0 : 1);}
                                        
int solve(int n,string s){
    vector<bool> storage(26,0);
    int result = 0;
    f(i,0,n){
        if(!storage[s[i]-'a']){
           storage[s[i]-'a'] = true;
           result = result + n- i;
        }
    }
    return result;
}
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int T=0;
    cin>>T;
    while(T--){
        int n;
        in n;
        string s;
        in s;
        int ans = solve(n,s);
        out ans nl;
    }             
  return 0;  
}