Submission #821288

#	Time	Username	Problem	Language	Result	Execution time	Memory
821288		vjudge1	Ancient Books (IOI17_books)	C++14	12 / 100	74 ms	284 KiB

books

#include<bits/stdc++.h>
#include "books.h"
#define fi first
#define se second
#define ll long long
using namespace std ;
ll ans = 1e18 ;
int sz ;
vector<int> now ;
bool check()
{
    vector<int> gr = now ;
    sort(gr.begin(), gr.end()) ;
    return (now == gr) ;
}
void rec(int ind, int cnt, int sum, int with)
{
    if(with == -1 && check())
    {
        ans = min(ans, (ll)sum + ind) ;
        return ;
    }
    if(cnt == 16)
        return ;
    if(with != -1)
    {
        swap(now[ind], with) ;
        rec(ind, cnt + 1, sum, with) ;
        swap(now[ind], with) ;
    }
    else
    {
        if(now[ind] != -1)
        {
            swap(now[ind], with) ;
            rec(ind, cnt + 1, sum, with) ;
            swap(now[ind], with) ;
        }
    }
    if(ind < sz - 1)
        rec(ind + 1, cnt + 1, sum + 1, with) ;
    if(ind)
        rec(ind - 1, cnt + 1, sum + 1, with) ;
}
ll minimum_walk(vector<int> p, int s)
{
    sz = p.size() ;
    if(sz <= 4)
    {
        now = p ;
        rec(s, 0ll, 0ll, -1ll) ;
    }
    return ans ;
}
//signed main()
//{
//    int n, s ;
//    cin >> n >> s ;
//    vector<int> p(n) ;
//    for(int i = 0 ; i < n ; i++)
//        cin >> p[i] ;
//    cout << minimum_walk(p, s) ;
//    return 0 ;
//}

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