Part I: Algorithm #1: infix to postfix Convert an infix expression to postfix: As long as there are more tokens, get the next token. if the token is an operand, append it to the postfix string. if the token is "(", push it onto the stack. if the token is an operator, (order operators by precedence) if the stack is empty, push the operator onto the stack. if the stack is not empty, pop operators of greater or equal precedence from the stack and append them to postfix string, stop when you encounter ")" or an operator of lower precedence or when the stack is empty. And then, push the new operator onto the stack. when you encounter a ")", pop operators off the stack and append them to the end of the postfix string until you encounter matching "(". when you reach the end of the infix string, append the remaining content of the stack to the postfix string. Algorithm #2: Evaluate postfix expressions (Self-study) Note: You must study this using the video prior to your lab. When an operand is entered, pushes it onto a stack. When an operator is entered, applies it to the top two operands of the stack. pops the operands from the stack. pushes the result of the operation on the stack. Part II: Complete method infixToPostfix in Expression class. Test it using the following infix expressions. A + B * C + D (A + B) * (C + D) A * B + C * D A + B + C + D