Question

Write a program that sorts a given list once in ascending and then in descending order without using the sort built-in function

Answer 1

Hi, @There,

Given an array of size n, arrange the first k elements of the array in ascending order and the remaining n-k elements in descending order.
Examples: 
 

Input: arr[] = {5, 4, 6, 2, 1, 3, 8, 9, -1}, k = 4 
Output: 2 4 5 6 9 8 3 1 -1
Input: arr[] = {5, 4, 6}, k = 2 
Output: 4 5 6 

# Python 3 program to sort first # k elements in increasing order # and remaining n-k elements in # decreasing # Function to sort the array def printOrder(arr, n, k): len1 = k len2 = n - k arr1 = [0] * k arr2 = [0] * (n - k) # Store the k elements # in an array for i in range(k): arr1[i] = arr[i] # Store the remaining n-k # elements in an array for i in range(k, n): arr2[i - k] = arr[i] # sorting the array from # 0 to k-1 places arr1.sort() # sorting the array from # k to n places arr2.sort() # storing the values in the # final array arr for i in range(n): if (i < k): arr[i] = arr1[i] else : arr[i] = arr2[len2 - 1] len2 -= 1 # printing the array for i in range(n): print(arr[i], end = " ") # Driver code if __name__ == "__main__": arr = [ 5, 4, 6, 2, 1, 3, 8, 9, -1 ] k = 4 n = len(arr) printOrder(arr, n, k) # This code is contributed # by ChitraNayal

Output:

2 4 5 6 9 8 3 1 -1