Submission #238950

#	Time	Username	Problem	Language	Result	Execution time	Memory
238950		dolphingarlic	PIN (CEOI10_pin)	C++14	50 / 100	100 ms	8552 KiB

pin

#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;

unordered_map<ll, int> cnt[16];

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, d;
    cin >> n >> d;
    FOR(i, 0, n) {
        string s;
        cin >> s;
        FOR(j, 0, 16) {
            ll hsh = 0;
            FOR(k, 0, 4) if (j & (1 << k))
                hsh += (s[k] - '0' + 1) << (k * 8);
            cnt[j][hsh]++;
        }
    }

    int ans = 0;
    FOR(i, 0, 16) {
        if (4 - __builtin_popcount(i) > d) continue;
        int contrib = 0;
        for (pair<ll, int> j : cnt[i])
            contrib += j.second * (j.second - 1) / 2;
        if ((d - 4 + __builtin_popcount(i)) & 1) ans -= contrib;
        else ans += contrib;
    }
    cout << ans;
    return 0;
}

• Subtask 1: 50 / 100