Submission #1121645

#	Time	Username	Problem	Language	Result	Execution time	Memory
1121645		vjudge1	Ice Hockey World Championship (CEOI15_bobek)	C++17	100 / 100	437 ms	20908 KiB

bobek

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

vector<ll> getSubsetSum(const vector<ll>& subset) {
    vector<ll> subsetSums;
    int n = subset.size();
    for (int i = 0; i < (1 << n); ++i) {
        ll sum = 0;
        for (int j = 0; j < n; ++j) {
            if (i & (1 << j)) {
                sum += subset[j];
            }
        }
        subsetSums.push_back(sum);
    }
    return subsetSums;
}

ll countWays(int N, ll M, const vector<ll>& costs) {
    vector<ll> leftHalf(costs.begin(), costs.begin() + N / 2);
    vector<ll> rightHalf(costs.begin() + N / 2, costs.end());

    vector<ll> leftSums = getSubsetSum(leftHalf);
    vector<ll> rightSums = getSubsetSum(rightHalf);

    sort(rightSums.begin(), rightSums.end());

    ll count = 0;
    for (ll leftSum : leftSums) {
        if (leftSum <= M) {
            count += upper_bound(rightSums.begin(), rightSums.end(), M - leftSum) - rightSums.begin();
        }
    }

    return count;
}

signed main() {
    cin.tie(nullptr)->sync_with_stdio(false);   

    int N;
    ll M;
    cin >> N >> M;
    vector<ll> costs(N);
    for (ll &i : costs) cin >> i;

    ll result = countWays(N, M, costs);

    cout << result << endl;
}   

• 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