public void infixToPostfix() {

//complete

}

public String getInfixExpression() {

//******COMPLETE *****

return null;

}

public String getPostfixExpression() {

//******COMPLETE *****

return null;

}

public double evaluate() {

//******COMPLETE *****

return -1;

}

public static void main(String[] args) {

//******COMPLETE *****

}