data structure

Algorithm for Evaluation of Postfix Expression Create an empty stack and start scanning the postfix expression from left to right. If the element is an operand, push it into the stack. If the element is an operator o, pop twice and get A and B respectively. Calculate BOA and push it back to the stack. When the expression is ended, the value in the stack is the final answer. Evaluation of a postfix expression using a stack is explained in below example: 2 10 + 96.1 push 2 push 10 pop 10 pop 2 push puh6 pop 6 pop Pop 3 pop 12 pop a 4 push 2 + 10 - 12 push 9.6 - 3 push 12/3-4 10 9 3 2 12 12 12