Please make sure that these infix and postfix equations have these outputs nothing else:

Infix:

(3 * 4 - (2 + 5)) * 4 / 2 = valid expression

10 + 6 * 11 -(3 * 2 + 14) / 2 = valid expression

Postfix:

9 3 / 6 / 4 * 10 - = -8

9 3 / 6 / 4 * -10 - = 12

(a) Using java.util.stack to write a java program to validate and calculate the result of each arithmetic Expression from input file (infix.dat). All equations from the input file are in traditional infix notation. Display each expression first. Then, if the arithmetic expression is not valid, display Invalid expression message and display the result of the calculation.

(b) Using java.util.Stack and java.util.StringTokenizer to write a java program to validate and calculate postfix expression from the input data file - postfix.dat

infix.dat

5 * 6 + 4 3 - 2 + ( 3 * 4 - (2 + 5)) * 4 / 2 10 + 6 * 11 -(3 * 2 + 14) / 2 2 * (12 + (3 + 5 ) * 2

postfix.dat

5 2 + 8 5 - * 2 4 - 5 2 * + 5 2 6 3 - * + 4 + 2 3 1 + * 7 5 0 / 9 3 / 6 / 4 * 10 - 3 / + 9 3 / 6 / 4 * 10 - 5 2 6 3 - * + 4 + 2 3 1 + * 7 - * 9 3 / 6 / 4 * -10 -