Stack

	- Implementation of Stack
		- Simple array based -
		- Dynamic array based -
		- Linked list based -
	- Check for balanced parantheses -
	- Infix to Postfix conversion -
	- Infix to Prefix conversion
	- Postfix evaluation -
	- Infix evaluation -----
	- Checking whether string is a palindrome -
	- Implement queue using two stacks -----
	- Implement stack using two queues -----
	- Given a Stack S and another empty Stack T and variable v, write a function that returns S but with its elements reversed
		(noob question -_-) -
	- Give an algorithm for finding duplicate parentheses in a expr -
		- Eg ((a+b)+((c+d)))
	- ***Reverse a stack using recursion -
	- ***Find minimum element in stack in O(1) time n O(n) space complexity (using another stack) -
	- Stock Span Problem
		- Link: http://www.geeksforgeeks.org/the-stock-span-problem/
	- Finding Next Greater Element
		- Link: http://www.geeksforgeeks.org/next-greater-element/