Submission #309825

#	Time	Username	Problem	Language	Result	Execution time	Memory
309825		CaroLinda	Ancient Books (IOI17_books)	C++14	0 / 100	2096 ms	416 KiB

books

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

#define debug printf
#define lp(i,a,b) for(int i = a ; i < b; i++)
#define pb push_back
#define ff first
#define ss second
#define mk make_pair
#define pii pair<int,int>
#define ll long long 
#define all(x) x.begin(),x.end()
#define sz(x) (int)(x.size())

const int MAX = 1e6+10 ;

using namespace std ;

//Tentando uma ideia (provavelmente vai dar errado mas vamos nessa)

int bit[MAX] ;
void upd(int pos, int val)
{
	for(int i = pos ; i < MAX ; i += i&-i )
		bit[i] = max(bit[i] , val) ;
}
int qry(int pos)
{
	int tot = -1 ;
	for(int i = pos ; i > 0 ; i -= i&-i )
		tot = max(tot, bit[i]);
	return tot ;
}


long long minimum_walk(vector<int> p, int s) 
{

	int n = sz(p) ;
	ll ans = 0LL ;

	lp(i,0,n) ans += (ll)(abs(p[i]-i)) ;

	int L = 0  ;
	int R = n-1 ;

	while(L < s && p[L] == L ) L++ ;
	while(R > s && p[R] == R) R-- ;

	vector<bool> vis( n, false ) ;
	vector<pii> intervalo(n, make_pair(-1,-1) ) ;

	for(int i = L ; i <= R ; i++ )
	{
		if(vis[i]) continue ;

		vector<int> List ;

		int x = i , l = i , r = i;
		while(!vis[x])
		{
			vis[x] = true ;
			List.push_back(x) ;
			
			l = min(l,x) ;
			r = max(r,x) ;

			x = p[x] ;
		}

		for(auto e : List ) intervalo[e] = make_pair(l,r) ;

	}

	vector<int> dist(n, n+5 ) ;
	priority_queue< pii , vector<pii> , greater<pii> > fila ;

	fila.push(make_pair(0,s)) ;
	dist[s] = 0 ;

	upd( intervalo[s].ff+1 , intervalo[s].ss ) ;

	while(!fila.empty())
	{
		int x = fila.top().ss ;
		int d = fila.top().ff ;
		fila.pop() ;

		if(dist[x] != d) continue ;

		vector<pii> adj ;

		if( x )
		{
			if( qry(x) >= x )
				adj.push_back(make_pair(x-1,0)) ;
			else adj.push_back(make_pair(x-1, 1)) ;
		}
		if(x+1 < n)
		{
			if( qry(x+1) >= x+1)
				adj.push_back(make_pair(x+1, 0)); 
			else adj.push_back(make_pair(x+1, 1 ) ) ;
		}

		for(auto e : adj)
		{
			int y = e.ff ;
			int cost = e.ss ;

			if(dist[y]<= cost+dist[x]) continue ;

			dist[y] = dist[x]+cost ;

			fila.push(make_pair(dist[y] , y ));
			upd( intervalo[y].ff+1, intervalo[y].ss ) ;

		}

	}

	ll toSum = dist[L] + dist[R] ;

	for(int i = L ; i <= s ; i++ )
		if(intervalo[i].ss >= s)
		{
			toSum -= dist[i] ;
			break ;
		}

	return ans + 2LL*toSum ;
}

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