Drawing Book | HackerRank Solution

Hello coders, today we are going to solve Drawing Book HackerRank Solution which is a Part of HackerRank Algorithm Series.

Task

A teacher asks the class to open their books to a page number. A student can either start turning pages from the front of the book or from the back of the book. They always turn pages one at a time. When they open the book, page 1 is always on the right side:

When they flip page 1, they see pages 2 and 3. Each page except the last page will always be printed on both sides. The last page may only be printed on the front, given the length of the book. If the book is n pages long, and a student wants to turn to page p, what is the minimum number of pages to turn? They can start at the beginning or the end of the book.

Given n and p, find and print the minimum number of pages that must be turned in order to arrive at page p.

Example

n = 5
p = 3
Using the diagram above, if the student wants to get to page 3, they open the book to page 1, flip 1 page and they are on the correct page. If they open the book to the last page, page 5, they turn 1 page and are at the correct page. Return 1.

Function Description

Complete the pageCount function in the editor below.

pageCount has the following parameter(s):

• int n: the number of pages in the book
• int p: the page number to turn to

Returns

• int: the minimum number of pages to turn

Input Format

The first line contains an integer n, the number of pages in the book.
The second line contains an integer, p, the page to turn to.

Constraints

• 1 <= n <= 10⁵
• 1 <= p <= n

Sample Input 0

6
2

Sample Output 0

1

Explanation 0

If the student starts turning from page 1, they only need to turn 1 page:

If a student starts turning from page 6, they need to turn 2 pages:

Return the minimum value, 1.

Sample Input 1

5
4

Sample Output 1

0

Explanation 1

If the student starts turning from page 1, they need to turn 2 pages:

If they start turning from page 5, they do not need to turn any pages

Return the minimum value, 0.

Solution – Drawing Book

C++

#include <vector>
#include <iostream>
#include <algorithm>

static int total_pages(const int& n) {
    return (n + 2) / 2;
}

int main() {
    
    int n,p;
    std::cin >> n >> p;
    
    int entire_book = total_pages(n);
    
    int from_front = total_pages(p) - 1;
    int from_back = entire_book - from_front - 1;
    
    std::cout << std::min(from_front, from_back) << '\n';
    
    return 0;
}

Python

import sys

n = int(input().strip())
p = int(input().strip())
print(min(p//2,n//2-(p//2)))

Disclaimer: The above Problem (Drawing Book) is generated by Hacker Rank but the Solution is Provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.