Editing 2019 Dec Bronze Problem 3 Livestock Lineup

== Official Problem Statement ==

[http://www.usaco.org/index.php?page=viewproblem2&cpid=965 Livestock Lineup]

==Problem Statement==

The USACO 965 problem, Livestock Lineup, is a classic problem of sorting. Given a list of N (1 ≤ N ≤ 10,000) cows, each with a unique ID number from 1 to N, you must arrange them in a line such that the absolute difference between the ID numbers of any two adjacent cows is as small as possible.

==Solution==

The solution to this problem is to sort the cows in ascending order according to their ID numbers. This can be done using a C++ implementation of the quicksort algorithm.

// C++ implementation of quicksort algorithm

void quicksort(int arr[], int left, int right) 
{ 
    int i = left, j = right; 
    int tmp; 
    int pivot = arr[(left + right) / 2]; 
  
    /* partition */
    while (i <= j) { 
        while (arr[i] < pivot) 
            i++; 
        while (arr[j] > pivot) 
            j--; 
        if (i <= j) { 
            tmp = arr[i]; 
            arr[i] = arr[j]; 
            arr[j] = tmp; 
            i++; 
            j--; 
        } 
    }; 
  
    /* recursion */
    if (left < j) 
        quicksort(arr, left, j); 
    if (i < right) 
        quicksort(arr, i, right); 
}

[[Category:Yearly_2019_2020]]
[[Category:Bronze]]
[[Category:Simulation]]
[[Category:Brute Force]]
[[Category:Sorting]]