Given an array, print the Next Greater Element (NGE) for every element.
//
// The Next greater Element for an element x is the first greater element on the right side of x in the array.
// Elements for which no greater element exist, consider the next greater element as -1.
//
// Example:
//
// Input: arr[] = [ 4 , 5 , 2 , 25 ]
// Output: 4 –> 5
// 5 –> 25
// 2 –> 25
// 25 –> -1
// Explanation: except 25 every element has an element greater than them present on the right side
//
// Input: arr[] = [ 13 , 7, 6 , 12 ]
// Output: 13 –> -1
// 7 –> 12
// 6 –> 12
// 12 –> -1
// Explanation: 13 and 12 don’t have any element greater than them present on the right side
