Submission #878230

#	Time	Username	Problem	Language	Result	Execution time	Memory
878230		alexdd	Bootfall (IZhO17_bootfall)	C++17	44 / 100	1014 ms	1364 KiB

bootfall

#pragma GCC optimize("O3,unroll-loops")
#include<bits/stdc++.h>
using namespace std;
int n,tot;
int a[505];
bitset<500005> dp;
int variante[500005],cntv;
int newv[500005],cntnew;
signed main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
        if(a[i]%2!=a[1]%2)
        {
            cout<<0;
            return 0;
        }
        tot+=a[i];
    }
    if(tot%2==1)
    {
        cout<<0;
        return 0;
    }
    for(int i=1;i<=tot;i++)
        if(i%2==a[1]%2)
            variante[++cntv]=i;
    for(int i=0;i<=n;i++)
    {
        dp.reset();
        dp[0]=1;
        for(int j=1;j<=n;j++)
        {
            if(i!=j)
                dp |= (dp<<a[j]);
        }
        if(i==0)
        {
            if(dp[tot/2]==0)
            {
                cout<<0;
                return 0;
            }
            continue;
        }
        cntnew=0;
        for(int j=1;j<=cntv;j++)
        {
            int x = variante[j];
            if((tot-a[i]+x)%2==0 && dp[(tot-a[i]+x)/2])
                newv[++cntnew] = x;
            ///tot - a[i] + x
        }
        cntv=cntnew;
        for(int j=1;j<=cntnew;j++)
            variante[j] = newv[j];
    }
    cout<<cntv<<"\n";
    for(int i=1;i<=cntv;i++)
        cout<<variante[i]<<" ";
    return 0;
}
/**
3
2 2 2
*/

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 0 / 21
• Subtask 6: 0 / 35