Submission #491453

#	Time	Username	Problem	Language	Result	Execution time	Memory
491453		Yazan_Alattar	Ice Hockey World Championship (CEOI15_bobek)	C++14	100 / 100	448 ms	8680 KiB

bobek

#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <list>
#include <utility>
#include <cmath>
#include <numeric>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 200007;
const ll inf = 1e18;
const ll mod = 1e9 + 7;
const double pi = acos(-1);
const int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};

vector <ll> v;
ll n, m, a[50], ans;

int main()
{
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin >> n >> m;
    for(int i = 0; i < n; ++i) cin >> a[i];
    for(int mask = 0; mask < (1 << (n / 2)); ++mask){
        ll sum = 0;
        for(int i = 0; i < n / 2; ++i) if((mask >> i) & 1) sum += a[i];
        v.pb(sum);
    }
    sort(all(v));
    for(int mask = 0; mask < (1 << ((n + 1) / 2)); ++mask){
        ll sum = 0;
        for(int i = n / 2; i < n; ++i) if((mask >> (i - n / 2)) & 1) sum += a[i];
        ans += upper_bound(all(v), m - sum) - v.begin();
    }
    cout << ans << endl;
    return 0;
}
// Don't forget special cases. (n = 1?)
// Look for the constraints. (Runtime array? overflow?)

• 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