Submission #161919

#	Time	Username	Problem	Language	Result	Execution time	Memory
161919		MvC	Bigger segments (IZhO19_segments)	C++11	37 / 100	536 ms	153916 KiB

segments

#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
using namespace std;
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=3e3+50;
const int mod=1e9+7;
int n,i,nr,j,t,mx[nmax];
ll a[nmax],f[nmax][nmax],pr[nmax];
vector<pair<ll,int> >vc[nmax];
vector<pair<ll,int> >::iterator it;
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];
		pr[i]=pr[i-1]+a[i];
	}
	for(i=0;i<=n;i++)for(j=0;j<=n;j++)f[i][j]=llinf;
	f[0][0]=0;
	vc[0].pb(mkp(0,0));
	for(i=1;i<=n;i++)
	{
		for(j=i;j<=n;j++)
		{
			it=(upper_bound(vc[i-1].begin(),vc[i-1].end(),mkp(pr[j],inf)));
			if(it!=vc[i-1].begin())
			{
				it--;
				t=it-vc[i-1].begin();
				f[i][j]=pr[j]-pr[mx[t]];
			}
			/*for(t=j-1;t>=0;t--)
			{
				if(f[i-1][t]<=pr[j]-pr[t])
				{
					f[i][j]=pr[j]-pr[t];
					break;
				}
			}*/
			if(f[i][j]<llinf)vc[i].pb(mkp(f[i][j]+pr[j],j));
		}
		if(!vc[i].empty())
		{
			sort(vc[i].begin(),vc[i].end());
			mx[0]=vc[i][0].sc;
		}
		for(j=1;j<(int)vc[i].size();j++)mx[j]=max(mx[j-1],vc[i][j].sc);
		if(f[i][n]<llinf)nr=max(nr,i);
	}
	cout<<nr<<endl;
	return 0;
}

Compilation message (stderr)

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

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 10 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27