Postfix Evaluation

The reason to convert infix to postfix expression is that we can compute the answer of postfix expression easier by using a stack.

For example:

For a postfix expression: 10 2 8 * + 3 -

We can use stack to solve it

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Create a class with two methods: a method named : public static int postfixEvaluate(String s) Parameter s is the a postfix expression: all the numbers are int, operators are from +, -, / *, The method should return the results main method which is used to test the postfixEvaluate(String s) Test case: "6 8 2 / 1 - * "8 5 * 7 4 2 + * + "2 3 + 4 5 * +"