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46. Re: Have a method return an array
807600 Jun 4, 2007 3:51 PM (in response to 807600)When you write the code, do you use Notepad or Textpad? 


49. Re: Have a method return an array
807600 Jun 4, 2007 6:15 PM (in response to 807600)I dont want to read the 5 page thread but would love to know the assignment details? May be you can catch up. i can see you are working hard in order to complete it and i am willing to help you. so please post your assignment. 
50. Re: Have a method return an array
807600 Jun 4, 2007 6:23 PM (in response to 807600)OK. This is the latest version of a program which factors a quadratic equation. There are a few minor bugs and some organization issues....
anyway, here you go:
class Factors{ private int value; int SolutionFac1, SolutionFac2; private int FacArray[][]; public int SolutionArray[] = new int[2]; public Factors(int value){ this.value = value; FacArray = new int[2][value]; } public int[][] FindFacs(int number){ int slot = 0; float modulus; int divisor, result; for(divisor = 1; divisor <= (number/2); divisor++){ if(number%divisor==0){ result = number/divisor; if(divisor <= result){ FacArray[0][slot]=divisor; FacArray[1][slot]=result; slot++; }; }; }; return FacArray; } public int[] TestA(int a){ FacArray[0][0] = SolutionFac1; FacArray[1][0] = SolutionFac2; SolutionArray[0] = SolutionFac1; SolutionArray[1] = SolutionFac2; return SolutionArray; } public int[] TestC(int c, int b){ for(int retrieval = 0; retrieval < c; retrieval++){ FacArray[0][retrieval] = SolutionFac1; FacArray[1][retrieval] = SolutionFac2; if((SolutionFac1 + SolutionFac2) == b) break; } SolutionArray[0] = SolutionFac1; SolutionArray[1] = SolutionFac2; return SolutionArray; } } public class EqnFac{ public static void main(String args[]){ int a = 6; int b = 6; int c = 9; Factors aFac = new Factors(a); Factors cFac = new Factors(c); aFac.FindFacs(a); cFac.FindFacs(c); aFac.TestA(a); cFac.TestC(c,b); System.out.print("Factored form of equation is: "); System.out.print( "(" + a + "x + " + cFac.SolutionFac1 + ")" ); System.out.print( "(x + " + cFac.SolutionFac2 + ")" ); } }

51. Re: Have a method return an array
807600 Jun 4, 2007 6:25 PM (in response to 807600)The most recent bugs like a method in class "main" trying to access variables outside its class haven't been fixed, so... 
52. Re: Have a method return an array
807600 Jun 4, 2007 6:26 PM (in response to 807600)In fact, before you try to edit it, let me revise. 
53. Re: Have a method return an array
807600 Jun 4, 2007 6:28 PM (in response to 807600)
Where is SolutionFac1 and 2 method? I dont see any methods in your program.System.out.print( "(" + a + "x + " + cFac.SolutionFac1 + ")" ); System.out.print( "(x + " + cFac.SolutionFac2 + ")" );

54. Re: Have a method return an array
807600 Jun 4, 2007 6:34 PM (in response to 807600)areyou just trying to find a factorial of a given number? 
55. Re: Have a method return an array
807600 Jun 4, 2007 6:49 PM (in response to 807600)Ok here is the kinda sorta better version. I'm trying to factor a quadratic equation, from "ax^2 + bx + c" to (_x + _)(_x +_). Look at this code (sorry it's such a mess, I write crappy code):
}class Factors{ private int value; private int SolutionFac1, SolutionFac2; private int FacArray[][]; public int SolutionArray[] = new int[2]; public Factors(int value){ this.value = value; FacArray = new int[2][value]; } public int[][] FindFacs(int number){ int slot = 0; float modulus; int divisor, result; for(divisor = 1; divisor <= (number/2); divisor++){ if(number%divisor==0){ result = number/divisor; if(divisor <= result){ FacArray[0][slot]=divisor; FacArray[1][slot]=result; slot++; }; }; }; return FacArray; } public void TestFacs(int c, int b){ for(int retrieval = 0; retrieval < c; retrieval++){ FacArray[0][retrieval] = SolutionFac1; FacArray[1][retrieval] = SolutionFac2; if((SolutionFac1 + SolutionFac2) == b) break; } } public int GetSolution1(){ return SolutionFac1; } public int GetSolution2(){ return SolutionFac2; } } public class EqnFac2{ public static void main(String args[]){ int a = 6; int b = 6; int c = 9; Factors aFac = new Factors(a); Factors cFac = new Factors(c); aFac.FindFacs(a); cFac.FindFacs(c); cFac.TestFacs(c,b); System.out.print("Factored form of equation is: "); System.out.print( "(" + a + "x + " + cFac.GetSolution1() + ")" ); System.out.print( "(x + " + cFac.GetSolution2() + ")" ); }

56. Re: Have a method return an array
807600 Jun 4, 2007 7:15 PM (in response to 807600)I haven't followed the entire thread, but if you're factoring quadratic equations, why would you need a 2d array?
First I would check to see if variable 'a' is equal to 1.
If so, then multiply 'a' * 'c'. Now you have to find what factors of (a * c) add/subtract to get the value of b.
Example
This is the first case I would test for. (a value being 1)// 1x^2 + 7x + 6 int a = 1; int b = 7; int c = 6 // Multiply a * c, which = 6 // So take note of the second sign in the equation which is a '+' // So what factors of (a * c) add up to 'b'. I know they have to add because // of the + sign in the second part. // So the factors of six are (1 * 6), (2 * 3) // (1 * 6) those numbers add up to 7! // so (x + 1) (x + 6) are your factors for 1x^2 + 7x + 6
If a isn't equal to one, I would divide the entire equation
by a in order to make the value a equal to one.
Are you trying to find the solution to this without using the quadratic equation? 
57. Re: Have a method return an array
807600 Jun 4, 2007 7:19 PM (in response to 807600)Yes, but I suppose the quadratic equation would make it 100 times eisier. I don't inderstand why you multiply a and c. The two conditions the factors must meet are:
1) The factors of c add to b
2) The factors of a multiply to a (so any combination of them would work) 
58. Re: Have a method return an array
807600 Jun 4, 2007 7:24 PM (in response to 807600)a and c are completely independent of each other, and a will most often be 1, as you said. 
59. Re: Have a method return an array
807600 Jun 4, 2007 7:25 PM (in response to 807600)It's just a simple trick I learned in my Math class a few years back.
Whatever the a values were, we multiplied it by c. Then we had to find the factors of that number that added/subtracted to get b.
It would always. Though sometimes it is a decimal/fraction, so that's when you need to use the quadratic equation(or that's what I would do)