Submission #90738

#	Time	Username	Problem	Language	Result	Execution time	Memory
90738		FutymyClone	Ice Hockey World Championship (CEOI15_bobek)	C++14	100 / 100	360 ms	17436 KiB

bobek

#include <bits/stdc++.h>

using namespace std;

const int N = 45;

int n;
long long a[N], m;
long long lef[1 << 20], rig[1 << 20], cntlef = 0, cntrig = 0;

int main(){
    scanf("%d %lld", &n, &m);
    for (int i = 1; i <= n; i++) scanf("%lld", &a[i]);
    for (int i = 0; i < (1 << (n / 2)); i++) {
        long long sum = 0;
        for (int j = 0; j < n / 2; j++) if (i & (1 << j)) sum += a[j + 1];
        lef[cntlef++] = sum;
    }

    for (int i = 0; i < (1 << (n - n / 2)); i++) {
        long long sum = 0;
        for (int j = 0; j < n - n / 2; j++) if (i & (1 << j)) sum += a[j + 1 + n / 2];
        rig[cntrig++] = sum;
    }

    sort(lef, lef + cntlef); sort(rig, rig + cntrig);
    long long ans = 0;
    for (int i = 0; i < cntlef; i++) ans += upper_bound(rig, rig + cntrig, m - lef[i]) - rig;
    printf("%lld", ans);
    return 0;
}

Compilation message (stderr)

bobek.cpp: In function 'int main()':
bobek.cpp:12:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %lld", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~~~
bobek.cpp:13:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for (int i = 1; i <= n; i++) scanf("%lld", &a[i]);
                                  ~~~~~^~~~~~~~~~~~~~~

• 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