Perl Weekly Challenge: Week 78

Challenge 1:

Leader Element

You are given an array @A containing distinct integers.

Write a script to find all leader elements in the array @A. Print (0) if none found.

An element is leader if it is greater than all the elements to its right side.

Example 1:

 Input: @A = (9, 10, 7, 5, 6, 1)
 Output: (10, 7, 6, 1)

Example 2:

 Input: @A = (3, 4, 5)
 Output: (5)

(Full code on Github.)

Challenge 2:

Left Rotation

You are given array @A containing positive numbers and @B containing one or more indices from the array @A.

Write a script to left rotate @A so that the number at the first index of @B becomes the first element in the array. Similary, left rotate @A again so that the number at the second index of @B becomes the first element in the array.

Example 1:

 Input:
     @A = (10 20 30 40 50)
     @B = (3 4)

Explanation:

 a) We left rotate the 3rd index element (40) in the @A to make it 0th index member in the array.
        [40 50 10 20 30]

 b) We left rotate the 4th index element (50) in the @A to make it 0th index member in the array.
        [50 10 20 30 40]

 Output:
     [40 50 10 20 30]
     [50 10 20 30 40]

Example 2:

 Input:
     @A = (7 4 2 6 3)
     @B = (1 3 4)

Explanation:

 a) We left rotate the 1st index element (4) in the @A to make it 0th index member in the array.
         [4 2 6 3 7]

 b) We left rotate the 3rd index element (6) in the @A to make it 0th index member in the array.
         [6 3 7 4 2]

 c) We left rotate the 4th index element (3) in the @A to make it 0th index member in the array.
         [3 7 4 2 6]

 Output:
     [4 2 6 3 7]
     [6 3 7 4 2]
     [3 7 4 2 6]

(Full code on Github.)