Submission #145428

#	Time	Username	Problem	Language	Result	Execution time	Memory
145428		mohammedehab2002	Ancient Books (IOI17_books)	C++11	20 / 100	34 ms	14200 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> p;
pair<int,int> dp[1005][1005];
bool calc[1005][1005];
int mn[1005][1005],mx[1005][1005],dist[1005][1005];
pair<int,int> solve(int l,int r)
{
	if (calc[l][r])
	return dp[l][r];
	if (mn[l][r]>=l && mx[l][r]<=r)
	return {l,r};
	calc[l][r]=1;
	if (mx[l][r]>r)
	return dp[l][r]=solve(l,mx[l][r]);
	return dp[l][r]=solve(mn[l][r],r);
}
long long minimum_walk(vector<int> pp,int s)
{
	p=pp;
	int n=p.size(),tl=0,tr=n-1;
	long long ans=0;
	for (int i=0;i<n;i++)
	{
		ans+=abs(p[i]-i);
		mn[i][i]=p[i];
		mx[i][i]=p[i];
		for (int j=i+1;j<n;j++)
		{
			mn[i][j]=min(mn[i][j-1],p[j]);
			mx[i][j]=max(mx[i][j-1],p[j]);
		}
	}
	if (!ans)
	return 0;
	queue<pair<int,int> > q;
	q.push(solve(s,s));
	while (!q.empty())
	{
		auto cp=q.front();
		q.pop();
		if (cp.first)
		{
			auto np=solve(cp.first-1,cp.second);
			if (!dist[np.first][np.second])
			{
				dist[np.first][np.second]=dist[cp.first][cp.second]+1;
				q.push(np);
			}
		}
		if (cp.second!=n-1)
		{
			auto np=solve(cp.first,cp.second+1);
			if (!dist[np.first][np.second])
			{
				dist[np.first][np.second]=dist[cp.first][cp.second]+1;
				q.push(np);
			}
		}
	}
	while (p[tl]==tl)
	tl++;
	while (p[tr]==tr)
	tr--;
	return ans+2*dist[tl][tr];
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 10
• Subtask 3: 0 / 28
• Subtask 4: 20 / 20
• Subtask 5: 0 / 30