# Stack

Here are some common approaches that can be used with the stack data structure:

1. **Iterative Approach**: This involves looping over the data and using a stack to keep track of elements. For example, you might use an iterative approach with a stack to traverse a tree or graph, convert an infix expression to postfix, or check for balanced parentheses in an expression.
2. **Recursive Approach**: Although not exactly the same as iteration, recursion is a related concept that often goes hand-in-hand with stacks. Recursion involves a function calling itself with modified arguments until a base case is reached. The call stack, which is an actual stack data structure, keeps track of these recursive calls.
3. **Dynamic Programming**: Stacks can be used in certain dynamic programming problems where the optimal solution can be found by making optimal choices at each step. For example, the largest rectangular area under a histogram can be found using a stack in a dynamic programming approach.
4. **Memoization**: Similar to dynamic programming, memoization involves storing the results of expensive function calls and reusing them when the same inputs occur again. While memoization is typically used with recursion, it can also be used with stacks in certain contexts.
5. **Divide and Conquer**: Stacks can be used in a divide-and-conquer approach where a problem is divided into smaller subproblems that are solved independently. The classic Tower of Hanoi problem can be solved using a divide-and-conquer approach with three stacks.

Remember, the choice of approach depends on the specific problem at hand. Understanding the problem and the data structure is key to choosing the most efficient approach.
