Submission #1481995

---

Source Code Expand

#include <iostream>
#include <vector>
#include <algorithm>
#include <utility>

using namespace std;
using llng = long long;
template<typename T> using v = vector<T>;
template<typename T> using vv = v<v<T> >;

int main() {
    int N; cin >> N;
    string S; cin >> S;

    if (N % 2 == 0) {
        cout << -1 << endl;
        return 0;
    }
    for (int i=1; i<N; i++) {
        if (S[i] == (S[i-1]-'a'+1)%3 + 'a') continue;
        cout << -1 << endl;
        return 0;
    }
    cout << (N-1)/2 << endl;
    return 0;
}

Submission Info

Judge Result