Submission #119138

#	Time	Username	Problem	Language	Result	Execution time	Memory
119138		tinjyu	Ancient Books (IOI17_books)	C++14	50 / 100	154 ms	16124 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
long long int tag[1000005];
int l[1000005],r[1000005];
long long int ans;
long long minimum_walk(std::vector<int> p, int s) {
	int n=p.size();
	int t=0;
	int far=0;
	for(int i=0;i<n;i++)
	{
		if(i==p[i])continue;
		ans+=abs(i-p[i]);
		if(i>p[i])
		{
			if(p[i]<s && s<i)
			{
				tag[s-1]--;
				tag[s+1]++;
			}
			tag[p[i]]++;
			tag[i]--;
		}
		else
		{
			if(p[i]<s && s<i)
			{
				tag[s-1]--;
				tag[s+1]++;
			}
			tag[i]++;
			tag[p[i]]--;
		}
	}
	
	for(int i=s+1;i<n;i++)tag[i]+=tag[i-1];
	int r=s;
	for(int i=n-1;i>=s;i--)
	{
		if(tag[i]!=0)
		{
			r=i+1;
			break;
		}
	}
	for(int i=s;i<r;i++)
	{
		if(tag[i]==0)ans+=2;
	}
	for(int i=s-1;i>=0;i--)tag[i]+=tag[i+1];
	r=0;
	for(int i=0;i<=s;i++)
	{
		if(tag[i]!=0)
		{
			r=i-1;
			break;
		}
	}
	for(int i=0;i<r;i++)
	{
		if(tag[i]==0)ans+=2;
	}
	return ans;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:9:6: warning: unused variable 't' [-Wunused-variable]
  int t=0;
      ^
books.cpp:10:6: warning: unused variable 'far' [-Wunused-variable]
  int far=0;
      ^~~

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