Submission #4024202

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Source Code Expand

#include<bits/stdc++.h>

#define pb push_back
#define mp make_pair

#define fi first
#define se second

typedef long long ll;

using namespace std;
string s;
ll cnt[27];

int main(){
cin >> s;
for(int i=0;i<s.size();i++){
    cnt[s[i] - 'a']++;
}
ll n = s.size();
ll res = (n * 1ll * (n - 1ll)) * 1ll / 2;
for(int i=0;i<26;i++){
    res -= (cnt[i] * 1ll * (cnt[i] - 1ll)) * 1ll / 2;
}
cout << res + 1;
return 0;
}

Submission Info

Judge Result