Submission #958264

#	Time	Username	Problem	Language	Result	Execution time	Memory
958264		MilosMilutinovic	도넛 (JOI14_ho_t3)	C++14	100 / 100	93 ms	3156 KiB

2014_ho_t3

#include<bits/stdc++.h>
 
#define pb push_back
#define fi first
#define se second
#define mp make_pair
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef long double ld;
 
template <typename T> bool chkmin(T &x,T y){return x>y?x=y,1:0;}
template <typename T> bool chkmax(T &x,T y){return x<y?x=y,1:0;}
 
ll readint(){
	ll x=0,f=1; char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
	return x*f;
}

int n;
int a[100005],nxt[100005];
ll pref[100005];

ll get(int l,int r){
	if(l<=r) return pref[r]-pref[l-1];
	else return pref[n]-(pref[l-1]-pref[r]);
}

bool check(ll x){
	if(pref[n]<x) return false;
	int ptr=1;
	for(int i=1;i<=n;i++){
		while(get(i,ptr)<x) ptr=(ptr%n)+1;
		nxt[i]=ptr;
		if(ptr==i) ptr=(ptr%n)+1;
	}
	for(int i=1;i<=n;i++){
		ll a=get(i,nxt[i]);
		ll b=get((nxt[i]%n)+1,nxt[(nxt[i]%n)+1]);
		ll c=get(nxt[(nxt[i]%n)+1]%n+1,nxt[nxt[(nxt[i]%n)+1]%n+1]);
		if(a+b+c<=pref[n]) return true;
	}
	return false;
}

int main(){
	n=readint();
	for(int i=1;i<=n;i++) a[i]=readint();
	for(int i=1;i<=n;i++) pref[i]=pref[i-1]+a[i];
	ll l=0,r=1e17,ans=0;
	while(l<=r){
		ll mid=(l+r)/2;
		if(check(mid)) ans=mid,l=mid+1;
		else r=mid-1;
	}
	printf("%lld\n",ans);
	return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 30 / 30
• Subtask 4: 50 / 50