Submission #1240023

#	Time	Username	Problem	Language	Result	Execution time	Memory
1240023		MasterDebater	K blocks (IZhO14_blocks)	C++20	100 / 100	123 ms	3780 KiB

blocks

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<ll,ll>
#define F first
#define S second
const int N=1e5+10,INF=1e18;
ll n,k,a[N],dp[N][2];
vector<pii>v;
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cin>>n>>k;
	for(int i=0;i<n;i++)cin>>a[i];
	for(int i=0;i<n;i++){
		if(i==0)dp[i][0]=a[i];
		else dp[i][0]=max(dp[i-1][0],a[i]);
	}
	for(int j=1;j<k;j++){
		v.clear();
		v.push_back({dp[j-1][0],0});
		ll ans=INF;
		for(int i=j;i<n;i++){
			ll zd=dp[i-1][0];
			while(!v.empty() and v.back().S<a[i]){
				pii nxt=v.back();
				v.pop_back();
				zd=min(zd,nxt.F);
			}
			if(v.empty() or zd+a[i]<v.back().F+v.back().S)v.push_back({zd,a[i]});
			dp[i][1]=v.back().F+v.back().S;
		}
		for(int i=0;i<n;i++)dp[i][0]=dp[i][1];
		//for(int i=0;i<n;i++)cout<<dp[i][0]<<' ';
		//cout<<'\n';
	}
	cout<<dp[n-1][0];
	return 0;
}

Compilation message (stderr)

blocks.cpp:7:24: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+18' to '2147483647' [-Woverflow]
    7 | const int N=1e5+10,INF=1e18;
      |                        ^~~~

• Subtask 1: 14 / 14
• Subtask 2: 18 / 18
• Subtask 3: 21 / 21
• Subtask 4: 47 / 47