Given a sorted array of integers, remove the duplicate elements from the array.

Given an array of integers which contains some zeros, move all the zeros to the end. The order of other elements should be preserved.

Write a function which takes an integer and returns its factorial using recursion.

Write a function which takes an unsorted array of numbers, and returns true if array consists of consecutive numbers.

Write a function which takes string and returns true if it is palindrome, false otherwise.