Submission #618010

#	Time	Username	Problem	Language	Result	Execution time	Memory
618010		StrawHatWess	Ancient Books (IOI17_books)	C++17	0 / 100	1 ms	340 KiB

books

#include "books.h"

#include <bits/stdc++.h>
using namespace std; 

typedef long long ll; 
typedef vector<int>vi;
#define pb push_back
#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()

#define FOR(i,a,b) for(int i=a; i<b; i++)

void dbgv(vi vec){for(int x: vec) cout << x << ' '; cout << endl; }

//---------------------------

int N; 
vi a,p; 

int check(){
	FOR(i,0,N) if(a[i]==-1 || p[a[i]]!=i) return 0; 
	return 1;  	
}

ll minimum_walk(vi p, int s) {
	::p=p; 
	N=sz(p); 
	a.resize(N); 
	iota(all(a),0); 

	int on=-1, i=s, ty=1;
	ll ans=0;  
	while(!check()){
		//dbgv(a); 
		if(a[i]!=-1 && p[a[i]]==i){
			i+=ty;
			ans++; 
			continue; 
		}

		swap(a[i],on); 

		if(on!=-1){
			if(i<p[on]) i++, ty=1; 
			else i--, ty=-1;
			ans++;
		}
	}
	ans+=i; 
	return ans; 
}


/*

4 0
0 2 3 1


*/

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