Submission #1076002

#	Time	Username	Problem	Language	Result	Execution time	Memory
1076002		Abito	Ancient Books (IOI17_books)	C++17	12 / 100	2075 ms	1048576 KiB

books

#include "books.h"
#include <bits/stdc++.h>
//#define int long long
#define pb push_back
using namespace std;
// first n is permutation , n is index, n+1 is book in hand
int n;
map<vector<int>,int> dis;
void bfs(vector<int> s){
	deque<vector<int>> q;
	q.push_front(s);
	dis[s]=0;
	while (!q.empty()){
		vector<int> v=q.front(),to;
		q.pop_front();
		// switch books
		to=v;
		to[v[n]]=v[n+1];
		to[n+1]=v[v[n]];
		if (dis.find(to)==dis.end()){
			dis[to]=dis[v];
			q.push_front(to);
		}
		// walk forward
		if (v[n]+1<n){
			to=v;
			to[n]=v[n]+1;
			if (dis.find(to)==dis.end()){
				dis[to]=dis[v]+1;
				q.push_back(to);
			}
		}
		//walk backwards
		if (v[n]-1>=0){
			to=v;
			to[n]=v[n]-1;
			if (dis.find(to)==dis.end()){
				dis[to]=dis[v]+1;
				q.push_back(to);
			}
		}
	}
}
long long minimum_walk(std::vector<int32_t> p, int32_t s) {
	n=p.size();
	vector<int> v;
	for (int i=0;i<n;i++) v.pb(i);
	v.pb(s);
	v.pb(n);
	bfs(v);
	v=p;
	v.pb(s);
	v.pb(n);
	return dis[v];
}

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