Submission #101753

#	Time	Username	Problem	Language	Result	Execution time	Memory
101753		cheeheng	Ice Hockey World Championship (CEOI15_bobek)	C++14	100 / 100	406 ms	20944 KiB

bobek

#include <bits/stdc++.h>

using namespace std;

long long A[45];

int main(){
    int N; long long M;
    scanf("%d%lld", &N, &M);

    for(int i = 0; i < N; i ++){
        scanf("%lld", &A[i]);
    }

    if(N <= 20){
        vector<long long> sum1;
        for(int i = 0; i < (1<<N); i ++){
            long long temp = 0;
            for(int j = 0; j < N; j ++){
                if(i&(1<<j)){
                    temp += A[j];
                }
            }
            sum1.push_back(temp);
        }
        sort(sum1.begin(), sum1.end());
        printf("%lld", (long long)(upper_bound(sum1.begin(), sum1.end(), M)-sum1.begin()));
    }else{
        vector<long long> sum1;
        for(int i = 0; i < (1<<20); i ++){
            long long temp = 0;
            for(int j = 0; j < 20; j ++){
                if(i&(1<<j)){
                    temp += A[j];
                }
            }
            sum1.push_back(temp);
        }
        vector<long long> sum2;
        for(int i = 0; i < (1<<(N-20)); i ++){
            long long temp = 0;
            for(int j = 0; j < (N-20); j ++){
                if(i&(1<<j)){
                    temp += A[j+20];
                }
            }
            sum2.push_back(temp);
        }
        sort(sum1.begin(), sum1.end());
        sort(sum2.begin(), sum2.end());
        long long ans = 0;
        for(int i = 0; i < (1<<20); i ++){
            ans += upper_bound(sum2.begin(), sum2.end(), M-sum1[i])-sum2.begin();
        }
        printf("%lld", ans);
    }
}

Compilation message (stderr)

bobek.cpp: In function 'int main()':
bobek.cpp:9:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%lld", &N, &M);
     ~~~~~^~~~~~~~~~~~~~~~~~
bobek.cpp:12:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         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