Submission #145405

#	Time	Username	Problem	Language	Result	Execution time	Memory
145405		mohammedehab2002	Ancient Books (IOI17_books)	C++11	50 / 100	195 ms	37588 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> p;
vector<pair<int,int> > c,d;
bool vis[1000005];
void dfs(int i)
{
	vis[i]=1;
	auto &x=c[c.size()-1];
	x.first=min(x.first,i);
	x.second=max(x.second,i);
	if (!vis[p[i]])
	dfs(p[i]);
}
long long minimum_walk(vector<int> pp,int s)
{
	p=pp;
	while (!p.empty() && p.back()+1==p.size())
	p.pop_back();
	int n=p.size();
	if (!n)
	return 0;
	long long ans=0;
	for (int i=0;i<n;i++)
	{
		ans+=abs(p[i]-i);
		if (!vis[i])
		{
			c.push_back({i,i});
			dfs(i);
		}
	}
	sort(c.begin(),c.end());
	for (auto x:c)
	{
		if (d.empty() || x.first>d.back().second)
		d.push_back(x);
		else
		d[d.size()-1].second=max(d[d.size()-1].second,x.second);
	}
	return ans+2*((int)d.size()-1);
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:19:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while (!p.empty() && p.back()+1==p.size())
                       ~~~~~~~~~~^~~~~~~~~~

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