Submission #1295615

#	Time	Username	Problem	Language	Result	Execution time	Memory
1295615		thesentro	Ice Hockey World Championship (CEOI15_bobek)	C++20	100 / 100	410 ms	21000 KiB

bobek

/*
 _____ _          ____             _             
|_   _| |__   ___/ ___|  ___ _ __ | |_ _ __ ___  
  | | | '_ \ / _ \___ \ / _ \ '_ \| __| '__/ _ \ 
  | | | | | |  __/___) |  __/ | | | |_| | | (_) |
  |_| |_| |_|\___|____/ \___|_| |_|\__|_|  \___/ 
*/
 
#include <bits/stdc++.h>
// #pragma GCC optimize("O3")
using namespace std;
#define ll long long

ll mod = 1e9+7;

ll binpow(ll a, ll b)
{
    ll res = 1;
    while (b>0)
    {
        if (b&1)
            res = (res*a)%mod;
        a = (a*a)%mod;
        b>>=1;
    }
    return res;
}
ll gcd(ll x, ll y)
{
    if (y==0)
        return x;
    return gcd(y, x%y);
}


void solve()
{   
    ll n,k;
    cin>>n>>k;
    vector<ll>v(n);
    for (int i=0 ; i<n ; i++)
        cin>>v[i];
    vector<ll>a,b;
    for (int m=0 ; m<(1<<(n/2)) ; m++)
    {
        ll sum=0;
        for (int i=0 ; i<(n/2) ; i++)
        {
            if (m&(1<<i))
                sum += v[i];
        }
        if (sum<=k)
            a.push_back(sum);
    }
    for (int m=0 ; m<(1<<((n+1)/2)) ; m++)
    {
        ll sum=0;
        for (int i=n/2 ; i<n ; i++)
        {
            if (m&(1<<(i-n/2)))
                sum += v[i];
        }
        if (sum<=k)
            b.push_back(sum);
    }
    ll res=0;
    sort(b.begin(), b.end());
    for (auto i:a)
        res += upper_bound(b.begin(), b.end(), k-i)-b.begin();
    cout<<res<<endl;
        
}
int main()

{
    // freopen ("input.txt","r",stdout);
    // freopen ("output.txt","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    ll tt = 1;
    // cin>>tt;
    while (tt--)
    {
        solve();
    }
    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