Submission #723602

#	Time	Username	Problem	Language	Result	Execution time	Memory
723602		MurotY	Hacker (BOI15_hac)	C++14	0 / 100	1 ms	340 KiB

hac

#pragma GCC optimize("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2")
#include <bits/stdc++.h>
#define ios ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ll long long
#define ull unsigned long long
#define ff first
#define ss second
#define all(a) a.begin(), a.end()
#define sz size()
using namespace std;
const double pi = 2 * acos(0.0);
const ll N=1e6+7, M=998244353;

ll a[N], pr[N];
void solve()
{
	int n;
	cin >> n;
	for (int i=0;i<n;i++) {
	     cin >> a[i];
		pr[i]=pr[max(0, i-1)]+a[i];
	}
	ll ans=0;
	for (int i=0;i<n;i++){
		int l=i, r=i;
		int lb=(n+1)/2, rb=n/2;
		int lf, rg;
		ll sum=0;
		if (l-lb+1 < 0){
			lf=n+(l-lb+1);
		//	cout << n << " " << l-lb+1 << "\n";
			if (lf == 0) sum=pr[l]+pr[n-1];
			else	sum=pr[l]+(pr[n-1]-pr[lf-1]);
		}
		else {
			lf=l-lb+1;
			if (lf == 0) sum=pr[l];
			else sum=pr[l]-pr[lf-1];
		}
	//	cout << sum << " ";
		ll sum1=sum;
		sum=0;
		if ((r+lb-1) > (n-1)){
			rg=(r+lb-1) % (n-1);
			rg--;
			if (r-1 < 0) sum=pr[n-1]+pr[rg];
			sum=(pr[n-1]-pr[r-1])+pr[rg];
		}
		else {
			if (r-1 < 0) sum=pr[r+lb-1];
			else sum=pr[l+rb-1]-pr[r-1];
		}
	//	cout << sum <<"\n";
		ans=max(ans, min(sum, sum1));
	}
	cout << ans;
	return ;
}
int main(){
	ios;
	int t=1;	
//	cin >> t;
	while (t--){ 
	    solve();
	    cout << "\n";
	}
	return 0;
}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 40