Submission #46900

#	Time	Username	Problem	Language	Result	Execution time	Memory
46900		SpaimaCarpatilor	Ancient Books (IOI17_books)	C++17	50 / 100	244 ms	111996 KiB

books

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

using namespace std;

int N, S, p[1000009], nxt[1000009];
bool ap[1000009];

long long minimum_walk (vector < int > pp, int ss)
{
    N = pp.size (), S = ss + 1;
    for (int i=1; i<=N; i++)
        p[i] = pp[i - 1] + 1;
    for (int i=1; i<=N; i++)
        if (ap[i] == 0)
        {
            int j = p[i], maxRight = i;
            ap[i] = 1;
            while (j != i)
                ap[j] = 1, maxRight = max (maxRight, j), j = p[j];
            nxt[i] = maxRight, j = p[i];
            while (j != i)
                nxt[j] = maxRight, j = p[j];
        }
    long long ans = 0;
    for (int i=1; i<=N; i++)
    {
        int curr = i - p[i];
        if (curr < 0) curr = -curr;
        ans += curr;
    }
    for (int i=1; i<N; i++)
        if (nxt[i] > nxt[i + 1])
            nxt[i + 1] = nxt[i];
    int target = 0;
    for (int i=1; i<=N; i++)
        if (p[i] != i)
            target = i;
    int pos = 1;
    while (pos < target)
    {
        if (pos == nxt[pos]) ans += 2, pos ++;
        else pos = nxt[pos];
    }
    return ans;
}

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