Submission #77116

#	Time	Username	Problem	Language	Result	Execution time	Memory
77116		zetapi	Bootfall (IZhO17_bootfall)	C++14	0 / 100	13 ms	5240 KiB

bootfall

#include "bits/stdc++.h"
using namespace std;

#define pb  push_back
#define mp  make_pair
#define ll  long long
#define int long long
#define itr iterator

typedef pair<ll,ll> pii;

const ll MAX=3e5+9;
const ll LIM=3e5;
const ll mod=1e9+7;

bitset<500*500+9> bs;

ll N,sum,arr[500*500+9],dp[500*500+9];

void TakeMod(ll &X,ll Y)
{
	while(X<0)
		X+=Y;
	while(X>=Y)
		X-=Y;
	return ;
}

void add(ll X)
{
	sum+=X;
	for(int A=500*500;A>=X;A--)
	{
		dp[A]+=dp[A-X];
		TakeMod(dp[A],mod);
	}
	return ;
}

void remove(ll X)
{
	sum-=X;
	for(int A=500*500;A<LIM;A++)
	{
		dp[A]-=dp[A-X];
		TakeMod(dp[A],mod);
	}
	return ;
}

signed main()
{
	ios_base::sync_with_stdio(false);

	dp[0]=1;
	cin>>N;
	for(int A=1;A<=N;A++)
	{
		cin>>arr[A];
		add(arr[A]);
	}
	if(sum%2 or (!dp[sum/2]))
		return cout<<0,0;
	for(int A=1;A<=500*500;A++)
		bs[A]=1;
	for(int A=1;A<=N;A++)
	{
		remove(arr[A]);
		for(int B=1;B<=500*500;B++)
			if(B>sum or (sum+B)%2 or (!dp[(sum+B)/2]))
				bs[B]=0;
		add(arr[A]);
	}
	vector<int> vec;
	for(int A=1;A<=sum;A++)
		if(bs[A])
			vec.pb(A);
	cout<<vec.size()<<"\n";
	for(auto A:vec)
		cout<<A<<" ";
	return 0;
}

Compilation message (stderr)

bootfall.cpp: In function 'void remove(long long int)':
bootfall.cpp:24:8: warning: iteration 9 invokes undefined behavior [-Waggressive-loop-optimizations]
  while(X>=Y)
        ^
bootfall.cpp:43:21: note: within this loop
  for(int A=500*500;A<LIM;A++)
                    ~^~~~

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