Poraka (државен '12) za 7/20

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

int main()
{
//    std::ios::sync_with_stdio(false);
//    freopen("in.txt", "r", stdin);
//    freopen("out.txt", "w", stdout);
    int n, k;
    cin >> n >> k;
    string p(n, ' ');
    for (int i = 0; i < n; ++i) {
        cin >> p[i];
    }
    map<string, int> m;
    string best_s;
    int best_s_cnt = -1;
    for (int i = 0; i+k < n; ++i) {
        string s = p.substr(i, k);
        if (++m[s] > best_s_cnt) {
            best_s_cnt = m[s];
            best_s = s;
        }
    }
    int counter = 0;
//    cout << "best_s=" << best_s << " count=" << best_s_cnt << endl;
    for (int i = 0; i < n; ++i) {
//        cout << "p[" << i << "]=" << p[i] << " best_s[" << i << "%" << k << "]=" << best_s[i%k] << " ";
        if (p[i] != best_s[i%k]) {
            p[i] = best_s[i%k];
            ++counter;
//            cout << "counter=" << counter;
        }
//        cout << endl;
    }
//    cout << "final p=" << p << endl << "counter=";
    cout << counter;
}