Submission #208167

#	Time	Username	Problem	Language	Result	Execution time	Memory
208167		SMani24	Ice Hockey World Championship (CEOI15_bobek)	C++11	100 / 100	272 ms	16888 KiB

bobek

//In the name of Allah
//SMani24
#include<bits/stdc++.h>
#define debug(x) cerr << #x << " = " << x << endl
#define int long long
using namespace std;

const int N = 42;

int n, m, ans;
int a[N], dpu[1 << (N / 2)], dpd[1 << (N / 2)], prep[1 << (N / 2)];

void set_prep() {
    for (int i = 0; i < N / 2; i++)
        prep[1 << i] = i;
}

void read_input() {
    cin >> n >> m;
    for (int i = 0; i < n; i++)
        cin >> a[i];
}
void solve() {
    set_prep();
    int nu = n / 2, nd = (n + 1) / 2;
    for (int mask = 1; mask < (1 << nu); mask++)
        dpu[mask] = dpu[mask ^ (mask & -mask)] + a[prep[mask & -mask]];
    for (int mask = 1; mask < (1 << nd); mask++)
        dpd[mask] = dpd[mask ^ (mask & -mask)] + a[prep[mask & -mask] + nu];
    sort(dpu, dpu + (1 << nu));
    sort(dpd, dpd + (1 << nd));
    for (int i = 0; i < (1 << nu); i++) {
        if (dpu[i] > m)
            break;
        ans += upper_bound(dpd, dpd + (1 << nd), m - dpu[i]) - dpd;
    }
}
void write_output() {
    cout << ans << endl;
}

int32_t main() {
    ios :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
    read_input(), solve(), write_output();
    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