Submission #1218716

#	Time	Username	Problem	Language	Result	Execution time	Memory
1218716		mariamp1	Ice Hockey World Championship (CEOI15_bobek)	C++20	100 / 100	391 ms	8520 KiB

bobek

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N;
    ll M;
    cin >> N >> M;
    vector<ll> cost(N);
    for(int i = 0; i < N; i++) cin >> cost[i];
    int N1 = N / 2;
    int N2 = N - N1;
    vector<ll> leftSums;
    leftSums.reserve(1 << N1);
    for(int mask = 0; mask < (1 << N1); mask++){
        ll sum = 0;
        for(int i = 0; i < N1; i++)
            if(mask & (1 << i))
                sum += cost[i];
        leftSums.push_back(sum);
    }
    sort(leftSums.begin(), leftSums.end());
    ll answer = 0;

    for(int mask = 0; mask < (1 << N2); mask++){
        ll sum2 = 0;
        for(int i = 0; i < N2; i++)
            if(mask & (1 << i))
                sum2 += cost[N1 + i];

        ll remain = M - sum2;
        if(remain < 0) continue;

        int cnt = upper_bound(leftSums.begin(), leftSums.end(), remain) - leftSums.begin();
        answer += cnt;
    }

    cout << answer << "\n";
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10