Add Infix to Postfix Converter using Stack (Java)

[Prasoon31Pandey]

This program converts an infix expression (like A+B*C) into a postfix expression (A B C * +) using the Stack data structure. It follows operator precedence and associativity rules to ensure the correct order of operations.

Example:
Input: A+BC
Output: ABC+

Time Complexity: O(n)
Space Complexity: O(n)

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