Trouble With Java Program using parameters and methods [closed] - methods

Question

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.
Closed 10 years ago.
I am stuck here with one programming code: Here are the instructions: http://my.fit.edu/~akhademzadeh2011/courses/cse1001/f2012/ass/ass04.pdf
And, this is my code:
import java.util.*;
public class PantherSolver {
public static void main(String[] args) {
Scanner kb = new Scanner(System.in);
String input;
String p = "0| |";
int signcontrol = 1;
input = GUI(p);
int firstnumber = inputmethod(input);
int firstsign = sign(input,signcontrol);
String secondp = p1(firstsign,firstnumber,p);
String input2 = GUI(secondp);
}
public static String p1(int firstsign,int firstnumber, String p) {
if (firstsign>0) {
p = "0| "+ firstnumber +" |";
}
else {
p = "0| -"+ firstnumber +" |";
}
return p;
}
public static String GUI1(String secondp) {
Scanner kb = new Scanner(System.in);
String newinput = kb.nextLine();
System.out.println(" 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ");
System.out.println(" ========================================");
System.out.println(secondp);
System.out.println("1|--------------------------------------|");
System.out.println("2| OFF +/- AC |");
System.out.println("3| 1 2 3 4 5 , |");
System.out.println("4| 6 7 8 9 0 SOLVE |");
System.out.println(" ========================================");
System.out.println(" Key: " + newinput +"");
return newinput;
}
public static String GUI(String p) {
Scanner kb = new Scanner(System.in);
System.out.println(" 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ");
System.out.println(" ========================================");
System.out.println(p);
System.out.println("1|--------------------------------------|");
System.out.println("2| OFF +/- AC |");
System.out.println("3| 1 2 3 4 5 , |");
System.out.println("4| 6 7 8 9 0 SOLVE |");
System.out.println(" ========================================");
String input1=kb.nextLine();
System.out.println(" Key: " + input1 +"");
return input1;
}
public static int inputmethod(String input) {
Scanner kb = new Scanner(System.in);
int a = 0;
if (input.length()==2) {
if((input.charAt(0)=='0')||(input.charAt(0)=='1')) {
;
}
else if((input.charAt(0)=='2') && !((input.charAt(1)==('0'))||(input.charAt(1)==('1'))||(input.charAt(1)==('2'))||(input.charAt(1)==('S'))||(input.charAt(1)==('T'))||(input.charAt(1)==('U'))||(input.charAt(1)==('V'))||(input.charAt(1)==('W'))||(input.charAt(1)==('X'))||(input.charAt(1)==('Y'))||(input.charAt(1)==('Z')))) {
;
}
else if((input.charAt(0)=='3') && !((input.charAt(1)==('0'))||(input.charAt(1)==('2'))||(input.charAt(1)==('4'))||(input.charAt(1)==('6'))||(input.charAt(1)==('8'))||(input.charAt(1)==('T'))||(input.charAt(1)==('U')))) {
;
}
else if((input.charAt(0)=='4') && !((input.charAt(1)==('0'))||(input.charAt(1)==('2'))||(input.charAt(1)==('4'))||(input.charAt(1)==('6'))||(input.charAt(1)==('8'))||(input.charAt(1)==('U'))||(input.charAt(1)==('V'))||(input.charAt(1)==('W'))||(input.charAt(1)==('X'))||(input.charAt(1)==('Y'))||(input.charAt(1)==('Z')))) {
;
}
else if ((input.equals("20")) || (input.equals("21")) ||(input.equals("22")) ||(input.equals("2S")) ||(input.equals("2T")) ||(input.equals("2U")) ||(input.equals("2V")) ||(input.equals("2X")) ||(input.equals("2Y")) ||(input.equals("2Z")) ||(input.equals("30")) ||(input.equals("32")) ||(input.equals("34")) ||(input.equals("36")) ||(input.equals("38")) ||(input.equals("40")) ||(input.equals("42")) ||(input.equals("44")) ||(input.equals("46")) ||(input.equals("48")) ||(input.equals("4U")) ||(input.equals("4V")) ||(input.equals("4W")) ||(input.equals("4X")) ||(input.equals("4Y")) ||(input.equals("4Z"))) {
switch(input) {
case "20":
case "21":
case "22":
OFF();
break;
case "2X":
case "2Y":
case "2Z":
main(null);
break;
case "30":
a = 1;
break;
case "32":
a = 2;
break;
case "34":
a = 3;
break;
case "36":
a = 4;
break;
case "38":
a = 5;
break;
case "40":
a = 6;
break;
case "42":
a = 7;
break;
case "44":
a = 8;
break;
case "46":
a = 9;
break;
case "48":
a = 0;
break;
case "4U":
case "4V":
case "4W":
case "4X":
case "4Y":
case "4Z":
solve();
break;
}
}
else {
System.out.println("Invalid key.");
System.out.println(" Key: " + input+"");
inputmethod(input);
}
}
else {
System.out.println("Invalid key.");
System.out.println(" Key: " + input +"");
inputmethod(input);
}
return a;
}
public static int sign (String input, int signcontrol) {
int sign1 = signcontrol;
if ((input.equals("2S")) ||(input.equals("2T")) ||(input.equals("2U")) ||(input.equals("2V"))) {
sign1 = sign1 * -1;
}
else {
sign1=1;
}
return sign1;
}
public static void OFF() {
System.exit(0);
}
public static void solve() {
}
}
Where do I go from here? I'm stuck in many places. Can someone guide me? First, I'm having problems with the methods. I used a couple of methods to display the "Panther Solver" and get the input.
The assignment asks to display the "Panther Solve", then the user picks what digits he/she wants. IE "32" means 2. This is very tricky though. If the user selects the +/- sign before a digit, it changes the value that he/she is about the input to a negative. It however does NOT display the negative sign right away, but only after he/she selects the digits.
Each time you select the digit and press enter, the screen pretty much reloads itself, and in the answer key, it displays what you typed. In the "0", row, it also displays what you just selected.
If you select the +/- sign after a digit is selected, nothing will happen. If you select any valid key that does not correlate to an input, nothing should happen. Just like the quadratic equation, with a,b,c, you type in your first response (a), then input comma, then go to b, then comma, then c, then solve. Each time you input, the input is evaluated.
In the input, all letters must be capitalized, if required, or else you would return and "Invalid Key". Also, for the equation, if a=0, return "Error".
I also have to formulate a solution for imaginary numbers, using i.
I am stuck in all parts. My questions are, where do I go from here in my code.
My first problem is getting the "Panther Solver" to display first, then accept the input. The next one is evaluated the negative/positive sign, and if it comes after or before the number. If it comes after, do nothing. If before, change the value to negative.
The other one is trying to make a loop for all of this in the main statement. Because for "a" in the quadratic equation, the user could want to enter "100". So I have to loop that.
Last, on the "0" row, I have to display the previous user input, just like an actual calculator. I'm having trouble getting that, and making it fit. For example, "a" starts at two spaces from the enter. Obviously as much input is entered, "a" moves to the left.
Thanks

Answer 1

Like all beginners, you're making the problem too difficult by failing to decompose it into small enough chunks.
Forget about user input and interfaces. Get the base solver algorithm working with hard wired inputs that you know the answer to. Write it, test it, and put it aside. Then start developing another class that deals only with getting input values and passing them to the class that actually does the work.
When you find yourself overwhelmed by too much detail, simplify the problem into smaller parts that you can deal with. Then knit them together to solve your larger problem.
It's call decomposition. It's the basis for all problem solving, especially programming and computer science.
For goodness' sake, it's solving a quadratic equation. Panther? Unnecessarily confusing.
Don't be fooled by the name. Forget about all that fancy output and get the base solver working. There are special cases you'll need to concern yourself with:
Two real roots.
One zero root, one real root.
Two complex conjugate roots.