Submission #101754

#	Time	Username	Problem	Language	Result	Execution time	Memory
101754		jamielim	Ice Hockey World Championship (CEOI15_bobek)	C++14	100 / 100	475 ms	8668 KiB

bobek

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

int n;
long long m;
long long arr[45];
int k,l;

int main(){
    scanf("%d%lld",&n,&m);
    for(int i=0;i<n;i++)scanf("%lld",&arr[i]);
    k=n/2; l=n-k;
    long long fh[(1<<k)];
    for(int i=0;i<(1<<k);i++){
        int bm=i;
        long long cur=0;
        while(bm&(-bm)){
            cur+=arr[__builtin_ctz(bm)];
            bm-=(bm&(-bm));
        }
        fh[i]=cur;
    }
    sort(fh,fh+(1<<k));
    long long ans=0;
    for(int i=0;i<(1<<l);i++){
        int bm=i;
        long long cur=0;
        while(bm&(-bm)){
            cur+=arr[__builtin_ctz(bm)+k];
            bm-=(bm&(-bm));
        }
        cur=m-cur;
        ans+=upper_bound(fh,fh+(1<<k),cur)-fh;
    }
    printf("%lld",ans);
}

Compilation message (stderr)

bobek.cpp: In function 'int main()':
bobek.cpp:10:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%lld",&n,&m);
     ~~~~~^~~~~~~~~~~~~~~~
bobek.cpp:11:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i=0;i<n;i++)scanf("%lld",&arr[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