Submission #1028671

#	Time	Username	Problem	Language	Result	Execution time	Memory
1028671		parsadox2	Ancient Books (IOI17_books)	C++17	50 / 100	87 ms	15956 KiB

books

#include "books.h"
#include <bits/stdc++.h>

using namespace std;

const int N = 1e6 + 10;

int a[N] , n;
bool marked[N];

long long minimum_walk(vector<int> p, int s) {
	n = p.size();
	long long ans = 0;
	int cnt = (p[0] == 0 ? 0 : 1);
	marked[p[0]] = true;
	for(int i = 1 ; i < n ; i++)
	{
		ans += max(2 * cnt , 2);
		if(p[i] > i)
		{
			cnt++;
			marked[p[i]] = true;
		}
		if(marked[i])
			cnt--;
	}
	for(int i = n - 1 ; i > s ; i--)
	{
		if(p[i] != i)
			break;
		ans -= 2;
	}
	for(int i = 0 ; i < s ; i++)
	{
		if(p[i] != i)
			break;
		ans -= 2;
	}
	return ans;
}

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