Submission #831740

#	Time	Username	Problem	Language	Result	Execution time	Memory
831740		finn__	Ancient Books (IOI17_books)	C++17	50 / 100	95 ms	14864 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
using L = long long;

long long minimum_walk(std::vector<int> p, int s)
{
    size_t const n = p.size();
    L ans = 0;
    for (int i = 0; i < n; ++i)
        ans += abs(i - p[i]);

    int first_non_id = 0, last_non_id = n - 1;
    while (first_non_id < n && p[first_non_id] == first_non_id)
        ++first_non_id;
    while (last_non_id >= 0 && p[last_non_id] == last_non_id)
        --last_non_id;

    first_non_id = min(first_non_id, s);
    last_non_id = max(last_non_id, s);

    int component_end = 0;
    for (int i = first_non_id; i <= last_non_id; ++i)
    {
        component_end = max(component_end, max(i, p[i]));
        if (component_end == i)
            ans += 2;
    }

    return ans - 2;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:10:23: warning: comparison of integer expressions of different signedness: 'int' and 'const size_t' {aka 'const long unsigned int'} [-Wsign-compare]
   10 |     for (int i = 0; i < n; ++i)
      |                     ~~^~~
books.cpp:14:25: warning: comparison of integer expressions of different signedness: 'int' and 'const size_t' {aka 'const long unsigned int'} [-Wsign-compare]
   14 |     while (first_non_id < n && p[first_non_id] == first_non_id)
      |            ~~~~~~~~~~~~~^~~

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