Submission #135205

#	Time	Username	Problem	Language	Result	Execution time	Memory
135205		anayk	Ancient Books (IOI17_books)	C++14	50 / 100	162 ms	14968 KiB

books

#include <iostream>

#include "books.h"

int min, max;
int l, r;
int n, low;

void add(int val)
{
	min = std::min(min, val);
	max = std::max(max, val);
}

long long minimum_walk(std::vector<int> p, int s)
{
	n = p.size();
	low = 0;
	long long answer = 0;

	for(int i = 0; i < p.size(); i++)
		answer += (long long) abs(i-p[i]);

	while(p[n-1] == n-1 && n-1 > s)
		n--;

	while(p[low] == low && low < s)
		low++;

	min = max = l = r = s;
	add(p[s]);

	while(min > low || max < n-1)
	{
		if(l > min)
		{
			l--;
			add(p[l]);
		}
		else if(r < max)
		{
			r++;
			add(p[r]);
		}
		else
		{
			answer += 2;
			if(max < n-1)
				max++;
			else
				min--;
		}
	}

	return answer;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:21:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < p.size(); i++)
                 ~~^~~~~~~~~~

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