For this project you will implement a simple calculator. your calculator is going to parse infix algebraic expressions, create the corresponding postfix expressions and then evaluate the postfix expressions. the operators it recognizes are: +, -, * and /. the operands are integers. your program will either evaluate individual expressions or read from an input file that contains a sequence of infix expressions (one expression per line). when reading from an input file, the output will consist of two files: postfix. txt that contains the corresponding postfix expressions one per line and results. txt that contains their evaluation, also one per line.