Submission #423615

#	Time	Username	Problem	Language	Result	Execution time	Memory
423615		arayi	Ancient Books (IOI17_books)	C++17	50 / 100	223 ms	24040 KiB

books

#include "books.h"
#include <bits/stdc++.h>
#define lli long long
#define ad push_back
#define fr first
#define sc second
#define MP make_pair
using namespace std;

const int N = 1e6 + 30;

int i1 = 1, n;
int col[N], a[N];
lli ans;
int dfs(int v)
{
    col[v] = i1;
    if(!col[a[v]]) return max(v, dfs(a[v]));
    return v;
}
long long minimum_walk(vector<int> p, int s)
{
	n = p.size();
	for(int i = 0; i < n; i++) a[i] = p[i], ans += abs(a[i] - i);
	int nx = -1;
	for(int i = 0; i < n; i++)
    {
        if(a[i] == i) continue;
        if(!col[i])
        {
            if(nx >= 0 && i > nx) ans += 2*(i - nx), i1++;
            nx = max(nx, dfs(i));
        }
    }
    int dz = -1, aj = -1;
    for(int i = s; i < n; i++)
    {
        if(col[i])
        {
            aj = i;
            break;
        }
    }
    for(int i = s; i >= 0; i--)
    {
        if(col[i])
        {
            dz = i;
            break;
        }
    }
    if(dz == -1 && aj == -1) return ans;
    else if(dz == -1) ans += 2*abs(aj - s);
    else if(aj == -1) ans += 2*abs(s - dz);
    else if(col[aj] == col[dz]) ans += 2*min(aj - s, s - dz);
    return ans;
}

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