Submission #152742

#	Time	Username	Problem	Language	Result	Execution time	Memory
152742		vex	K blocks (IZhO14_blocks)	C++14	53 / 100	1040 ms	42876 KiB

blocks

#include<bits/stdc++.h>
#define maxn 100005
#define INF (int)(1e9 + 77)
using namespace std;

int n,k;
int a[maxn];
int dp[maxn][102];
int lv[maxn];


int tree[4*maxn];
void build(int v,int l,int r,int ind)
{
	if(l>r)return;
	
	if(l==r)
	{
		tree[v]=dp[l][ind];
		return;
	}
	
	int mid=(l+r)/2;
	build(2*v,l,mid,ind);
	build(2*v+1,mid+1,r,ind);
	tree[v]=min(tree[2*v],tree[2*v+1]);
}

int query(int v,int l,int r,int lt,int rt)
{
	if(l>r || l>rt || lt>r)return INF;
	
	if(lt<=l && r<=rt)return tree[v];
	
	int mid=(l+r)/2;
	
	return min(query(2*v,l,mid,lt,rt), query(2*v+1,mid+1,r,lt,rt));
}


int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	
	cin>>n>>k;
	for(int i=1;i<=n;i++)cin>>a[i];
	
	stack<int>ms;
	ms.push(0);
	a[0]=INF;
	for(int i=1;i<=n;i++)
	{
		while(!ms.empty())
		{
			int vrh=ms.top();
			if(a[vrh]<=a[i])
			{
				ms.pop();
			}
			else break;
		}
		
		lv[i]=ms.top();
		ms.push(i);
	}
	
	//for(int i=1;i<=n;i++)cout<<lv[i]<<" ";cout<<endl;
	
	for(int i=0;i<=n;i++)
		for(int j=0;j<=k;j++)dp[i][j]=INF;
	dp[0][0]=0;
	
	for(int i=1;i<=n;i++)dp[i][0]=INF;
	for(int j=1;j<=k;j++)
	{
		build(1,0,n,j-1);
		for(int i=1;i<=n;i++)
		{
			dp[i][j]=min( dp[ lv[i] ][j], query(1,0,n,lv[i],i-1)+a[i]);
		}
	}
	
	cout<<dp[n][k];
	return 0;
}

• Subtask 1: 14 / 14
• Subtask 2: 18 / 18
• Subtask 3: 21 / 21
• Subtask 4: 0 / 47