Submission #1542330

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

int main()
{
    string A;
    cin >> A;

    int N = A.size();

    vector<vector<long long>> cnt(N, vector<long long>(26, 0));    
    for (int i = 0; i < N; i++) {
        cnt[i][A[i] - 'a']++;
    }

    for (int i = N - 1; i > 0; i--) {
        for (int j = 0; j < 26; j++) {
            cnt[i - 1][j] += cnt[i][j];
        }
    }

    long long ans = 1;
    for (int i = 0; i < N; i++) {
        ans += (N - i) - cnt[i][A[i] - 'a'];
    }
    cout << ans << endl;
    return 0;
}

Submission Info

Judge Result