Submission #163787

#	Time	Username	Problem	Language	Result	Execution time	Memory
163787		MvC	Bootfall (IZhO17_bootfall)	C++11	100 / 100	550 ms	2044 KiB

bootfall

#pragma GCC target("avx2")
#pragma GCC optimization("O3")
#pragma GCC optimization("unroll-loops")
#include <bits/stdc++.h>
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define mkp make_pair
#define in insert
#define er erase
#define fd find
#define fr first
#define sc second
typedef long long ll;
typedef long double ld;
const ll INF=0x3f3f3f3f3f3f3f3f;
const ll llinf=(1LL<<62);
const int inf=(1<<30);
const int nmax=5e2+5;
const int mmax=500*500+5;
const int mod=1e9+7;
using namespace std;
int n,a[nmax],i,j,sm,f[mmax];
bitset<mmax>bs;
int main()
{
	//freopen("sol.in","r",stdin);
	//freopen("sol.out","w",stdout);
	//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
	ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
	cin>>n;
	for(i=1;i<=n;i++)cin>>a[i],sm+=a[i];
	if(sm&1)rc(0);
	f[0]=1;
	sm=0;
	for(i=1;i<=n;i++)
	{
		for(j=sm+a[i];j>=a[i];j--)
		{
			f[j]+=f[j-a[i]];
			if(f[j]>=mod)f[j]-=mod;
		}
		sm+=a[i];
	}
	if(!f[sm/2])rc(0);
	for(i=1;i<=sm;i++)bs[i]=1;
	for(i=1;i<=n;i++)
	{
		for(j=a[i];j<=sm;j++)
		{
			f[j]-=f[j-a[i]];
			if(f[j]<0)f[j]+=mod;
		}
		for(j=1;j<=sm;j++)
		{
			if((sm-a[i]+j)&1 || !f[(sm-a[i]+j)/2])bs[j]=0;
		}
		for(j=sm;j>=a[i];j--)
		{
			f[j]+=f[j-a[i]];
			if(f[j]>=mod)f[j]-=mod;
		}
	}
	cout<<bs.count()<<endl;
	for(i=1;i<=sm;i++)if(bs[i])cout<<i<<" ";
	cout<<endl;
	return 0;
}

Compilation message (stderr)

bootfall.cpp:2:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization("O3")
 
bootfall.cpp:3:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization("unroll-loops")

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