Submission #427013

#	Time	Username	Problem	Language	Result	Execution time	Memory
427013		Hazem	Ancient Books (IOI17_books)	C++14	0 / 100	219 ms	288 KiB

books

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

using namespace std;

const LL LINF  = 1e18;

int a[10],n;
vector<int>vec;

bool check(){

	bool q = 1;
	for(int i=0;i<n;i++)
		q &= (a[i]==vec[i]);
	
	return q;
}

LL bt(int pos,int cur,int cnt);

LL move(int pos,int cur,int cnt){

	LL ret = LINF;

	if(pos<n-1)
		ret = min(ret,bt(pos+1,cur,cnt+1));
	
	if(pos>0)
		ret = min(ret,bt(pos-1,cur,cnt+1));

	return ret;
}

LL bt(int pos,int cur,int cnt){

	if((cur==-1)&&!pos&&check())
		return cnt;
	
	if(cnt>12)
		return LINF;

	LL ret = LINF;
	ret = min(ret,move(pos,cur,cnt));
	
	if(cur==-1){
		cur = a[pos];
		a[pos] = -1;
		ret=  min(ret,move(pos,cur,cnt));
		a[pos] = cur;
		cur = -1;
	}

	if(a[pos]==-1){
		a[pos] = cur;
		cur = -1;
		ret = min(ret,move(pos,cur,cnt));
		cur = a[pos];
		a[pos] = -1;
	}

	if(cur>=0&&a[pos]>=0){
		swap(cur,a[pos]);
		ret = min(ret,move(pos,cur,cnt));
		swap(cur,a[pos]);
	}

	return ret;
}

long long minimum_walk(std::vector<int> P, int s) {	
	
	vec = P;
	n = P.size();
	for(int i=0;i<n;i++)
		a[i] = i;
		
	return bt(0,-1,0);
}

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