Submission #850864

#	Time	Username	Problem	Language	Result	Execution time	Memory
850864		dungz	Growing Vegetables is Fun 4 (JOI21_ho_t1)	C++17	100 / 100	22 ms	10240 KiB

Main

//#pragma GCC optimize ("O2")
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define task "task"
#define task "task"
#define prll pair<ll,ll>
#define pb push_back
#define ld long double
const ll MIN=-1e18,MAX=1e18,MOD=1e9+7,nmax=200005;
ll a[nmax],h1[nmax],h2[nmax],cost1[nmax],cost2[nmax];
int main(){
   	//freopen (task".inp", "r", stdin);
   	//freopen (task".out", "w", stdout);
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	int n;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
	}
	h1[1]=a[1];
	for(int i=2;i<=n;i++)
	{
		if(a[i]<=a[i-1])
		{
			cost1[i]=cost1[i-1]+a[i-1]-a[i]+1;
			h1[i]=h1[i-1]+1;
		}
		else
		{
			cost1[i]=cost1[i-1];
			h1[i]=max(h1[i-1]+1,a[i]);
		}
	}
	h2[n]=a[n];
	for(int i=n-1;i>=1;i--)
	{
		if(a[i]<=a[i+1])
		{
			cost2[i]=cost2[i+1]+a[i+1]-a[i]+1;
			h2[i]=h2[i+1]+1;
		}
		else
		{
			cost2[i]=cost2[i+1];
			h2[i]=max(h2[i+1]+1,a[i]);
		}
	}
//	for(int i=1;i<=n;i++)
//	{
//		cout<<cost1[i]<<" ";
//	}
//	cout<<endl;
//	for(int i=1;i<=n;i++)
//	{
//		cout<<h1[i]<<" ";
//	}
//	cout<<endl;
//	for(int i=1;i<=n;i++)
//	{
//		cout<<cost2[i]<<" ";
//	}
//	cout<<endl;
//	for(int i=1;i<=n;i++)
//	{
//		cout<<h2[i]<<" ";
//	}
//	cout<<endl;
//	cout<<cost1[3]<<" "<<cost2[4];
	ll ans=min(cost2[1],cost1[n]);
	for(int i=2;i<n;i++)
	{
		ans=min(ans,max(cost1[i],cost2[i+1])+(h1[i]==h2[i+1]));	
	}
	cout<<ans;
}
/*
8
12 2 34 85 4 91 29 85
 
 
*/

• Subtask 1: 40 / 40
• Subtask 2: 60 / 60