10-26 Exercise 3: Find roots of a quadratic equation

Question

Write a program to find roots of a quadratic equation

A quadratic equation is a second order equation having a single variable. Any quadratic equation can be represented as where a, b and c are constants ( a can't be 0) and x is unknown variable. 

寫一個找二次方程的求根程式

For Example

 is a quadratic equation where a, b and c are 2, 5 and 3 respectively.

To calculate the roots of quadratic equation we can use below formula. There are two solutions of a quadratic equation.

使用下列公式:

x = (-b + sqrt(D))/(2*a)
x = (-b - sqrt(D))/(2*a)

where, D = (b*b-4*a*c) is Discriminant (判別式), which differentiate the nature of the roots of quadratic equation.

For the complex result (複數根):

realPart = -b/(2*a);
imaginaryPart =sqrt(-D)/(2*a);

Note: We have used sqrt() function to find square root which is in math.h library.

 

Example input 1:

1 2 1

Example output 1:

Roots of 1.00x^2 + 2.00x + 1.00 = 0 are real and same
x1 = x2 = -1.00

 

Example input 2:

1 -3 2

Example output 2:

Roots of 1.00x^2 + -3.00x + 2.00 = 0 are real and different
x1 = 2.00
x2 = 1.00

 

Example input 3:

1 2 2

Example output 3:

Roots of 1.00x^2 + 2.00x + 2.00 = 0 are complex and different
x1 = -1.00+1.00i
x2 = -1.00-1.00i

Comments

We will continue this question in few days

---

Everything is fixed. Enjoy your time with The Judge :)

---

ANNNNNNNNNNNNNNNNNNNNNNNNNNGRYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

---

Your code has newline at the end sometime. You learned this lesson many times!

---

After i correct the newline in my code,there is still wrong output.However,I had run the program in Codeblocks.The output is still as well as the result. Seeking for help.

---

your output lack of 1 space at line 8 when print out "Roots of ...". Please be careful with all small details when working with online judge

Answer 1

Hidden content!
#include <stdio.h>
*** * *    **** **    ***
int main()
{
*****    * ***  ******  *  *  ** **    **** ** ** **    *** 
 *** *    * * **** * *  ** ** **    * %f   *  *    ** *     * *  * * *     
 ** *** *** **  * ***    = (b*b-4*a*c);
  **   *** * *    ** * **  *  = (-b + sqrt(D))/(2*a);
* *   *   *      **   * * **  = (-b - sqrt(D))/(2*a);
       *** ** * *    * ***   = -b/(2*a);
*    *  ** *  ********** *** ** * =sqrt(-D)/(2*a);
*** **  **  * **  *  *    * * *  ****  
***   * ******  **  ** 
 ***   * *   ***  ******  * *  **    *      *** * * **  *** *  * * of %.2fx^2 + %.2fx + %.2f = 0 are real and     * **  *        
*  ** * * *   *  * *** *  *  ** **** *     *** * * ** *  * * *  = %.2f\nx2 = %.2f",x1,x2);
 * ***      **  *   *** *   

** ****  ** * * ***** **   **** if(D==0)
  *    *** ** ** **** *****  *
*** *  * * *** **  * **      *** ***  **** ***  ****** ** ** *** *   *  of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
 *    * * * ** * **   ** **    * * *  **  *** ** **    ***  *   ***        = x2 = %.2f",x1);
**     ** ***   *  *** *    **  
**        *    ***** * ** 
*****   *  *** ***  **    
***   *** ** ** *** *    *** ** ** *  * ** ** **  * *  *     *** *  * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and  * ** *   ****     * 
   ** * *** * *   * ** **  *  ***  *      *   ** *          *****      =  * *    **  **    **  * * * *   *
 **** **     *  **     ** ** **    * *****  * *    * * ** *  ** ** = * * ** *** **    ** *  *****    
 *** *   *  ** **  **   * 
      ** ****        **     ** 0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 2

Hidden content!
#include <stdio.h>
*  *****   * **  **
int main()
{
******* *   *   *  *  **  *   *  *  * * * *   ** **** ***   ** *
*    * *     ** * **     *     **  %f   *       ** *** **** **   ******* 
   *   *  ***  * *  * * ** = (b*b-4*a*c);
* ** *** ***  *  **** * *   ***  = (-b + sqrt(D))/(2*a);
 *   * *  *  *    *  **  * * = (-b - sqrt(D))/(2*a);
  *      **** ** *     *    * *   = -b/(2*a);
**  * * *   *** *   ***  *  *    * =sqrt(-D)/(2*a);
 *** *  ** * ** * ***  *  *  *  *
 **  ****   **   **    ** **
 ***** * * *   * **  * *  *  * * **  * * **   ***   **   * ** *  *** of %.2f x^2 + %.2f x + %.2f = 0 are real and    ******* * ** ****
 ****   * *  *      *   ** *    **  * * *  **  ** ****   *  * *  **** = %.2f\nx2 = %.2f",x1,x2);
 * * *  * ***   * ****  

 ** *   **  * *  **  * * if(D==0)
* **  *** *    *    ****  ** * 
* ****** *** **  *   * * *  *  **** ** *****   * *** ** **  *    *** of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
** *     * * * *******    **** ** ***   **  ***   ***** *   ***  * *  = x2 = %.2f",x1);
*  **** *      ***   ** *   
* **** ** *  **** ** ** ****    
 **   * * **    **     **
*   *    ********* * *  * **** **** *  * *  ** **** * * * ** * *  ** of %.2fx^2 + %.2fx + %.2f = 0 are complex and * * *** * **   *   
  **   * * * ** * * * *******    * ** **** * ** ** **  *  * ***** ** * ****  = ***  *  * *  *  ** *  **     
   ****** * ** * *  *    * * * *****  *  **   *** *      ***   = *  ****  * * ****    * ** *  
***   * *   **     **  ** *
** ****  *  *** * *   *    **  * 0;
}

Comments

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output
Case 3: Wrong output

Answer 3

Hidden content!
#include <stdio.h>
#include <stdlib.h>

int main()

{
 ** ** *** *    *  *   * *  ** * * a,b,c,x1,x2,D=0;
*     * * ** * ***  ** * *** *  
***  * *** *** *    *  *  * **  **    ** ** * %f   ***   *     *      * *   **** 
      **   ** **** **** *  
* * *  * **    ***********      *  **
*  **  **** * *  * **    ** *   + sqrt(D))/(2*a);
* * * **  *  * *  *** *  * * *   *    - sqrt(D))/(2*a);
   *  *  ** **  * * * * * 
* ***  * *  * *   * *    ** ***
*  * **    *** *****     **   *
  *** ***  *    *   * **   ** * * *  **** ** ** *   * * * **  **  * * of %.2fx^2+%.2fx+%.2f=0 are complex and   * * **  *  ****  *      *    **** 
** * ***   *   * *** ** *  
* ***    ** **   ***** **  *   
** *   **  ** ***  * **  ** *    * if(D==0)
** ** ***       *   *  *      *
*  *  *        **    *  **  *   * *  *   *  **  *   * *** * of %.2fx^2+%.2fx+%.2f=0 are real and same\nx1=x2=%.2f",a,b,c,x1);
 *  *****    * *** ** ***
     *** **  *** **    ** 
*   **  * *  ** *** *     * * * 
* * *  * *     * *       ***
 * ***   * **    **   **  *****  ** *  *******  *** *  * *  *****  **** *  of %.2fx^2+%.2fx+%.2f=0 are real and ** * ******    * * *  **  ****  ***  
* *  *** ******  ****** ** 
    * *  ** **   *  *    ** **
  ****** ***** *  ** ******
  * *  * * ** ***     * * *   *  0;
}

Comments

prog.c: In function 'main':
prog.c:12:14: warning: implicit declaration of function 'sqrt' [-Wimplicit-function-declaration]
     x1=(-b + sqrt(D))/(2*a);
              ^~~~
prog.c:12:14: warning: incompatible implicit declaration of built-in function 'sqrt'
prog.c:12:14: note: include '<math.h>' or provide a declaration of 'sqrt'

Answer 4

Hidden content!
*     *    *  * *****
int main()
{
 *    ***** **  *** **** * a,b,c,D;
***    ** ***   ****  ***   * x1,x2,r,i;
 ****   * ***    ****** ***  ** ***  *  * * *  *  **** *  ******  **  * ****
*   *   **  ***    * *   *  * * **     
  *  *  *    *  ** ****** *  **   * * ** 
*** *   **      **   * *  *   *   * * ** 
 ********  *  *   * *** *****    *  
***  * *   * *** * ***  * 
 * * *   ******  * **  ** * * **  ** ** *** ** * * ** * **    **  * **** * of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
  * *  **** *****  *** *   * **  ** ****   **     *** *   **** = x2 = %.2f",x1);
* *  *  ** * ** *  ** *  *
** **   *   ***** ** *** if(D>0)
*     * * *  **  * **** * ****
* ** * **  ***     *  * ***   * ***** **  * ***** * **** * ** ***   of %.2fx^2 + %.2fx + %.2f = 0 are complex and **** **  ** * *  *
 **  ***  ****  *  *   *  * **     * ** *     *  *  * *   *  *   = %.2f\n",x1);
 *  *    ****  * ***  ** *****  * * * *   **     *** **    *  = %.2f",x2);
* * *** * * * *   * *  *  * 
**  ** *    ****** **  **    if(D<0)
 * *** *** *****  ****  **
 * ***  ***  *****   *** ****** **  *** *  *   *  ** *   *****  ** of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
* * **   * *  * *** *  *  ** * * *  *      *     **  -b/(2*a);
 **  *   **     * ***** ****   ***   *    **     **  ***   
*   *** * **  ***** * * **    *   *** **   *    ** *  **** * = %.2f+%.2fi\n",r,i);
  *   *******  ***  * * ** ****  * **** *   * *  **  * *  * *    * = %.2f-%.2fi",r,i);
* * * * *   * *** * ** ** 
}

Comments

prog.c: In function 'main':
prog.c:6:5: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
     scanf("%f%f%f",&a,&b,&c);
     ^~~~~
prog.c:6:5: warning: incompatible implicit declaration of built-in function 'scanf'
prog.c:6:5: note: include '<stdio.h>' or provide a declaration of 'scanf'
prog.c:12:9: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
         printf("Roots of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
         ^~~~~~
prog.c:12:9: warning: incompatible implicit declaration of built-in function 'printf'
prog.c:12:9: note: include '<stdio.h>' or provide a declaration of 'printf'
prog.c:17:9: warning: incompatible implicit declaration of built-in function 'printf'
         printf("Roots of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
         ^~~~~~
prog.c:17:9: note: include '<stdio.h>' or provide a declaration of 'printf'
prog.c:23:9: warning: incompatible implicit declaration of built-in function 'printf'
         printf("Roots of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
         ^~~~~~
prog.c:23:9: note: include '<stdio.h>' or provide a declaration of 'printf'

Answer 5

Hidden content!
 * ******** *  **
int main()
{
 * ** * ***   * ** * * *  ** a,b,c,D;
*     *  ** *  *  *  ** ** **  x1,x2,r,i;
  *** **    **   ** *   *   ****  ******  * *   ***   ***  **    *   
* * ** **   ** ******  ** *   ** * 
* **  *   **********  ****   ** **** * *
* *  ** *    * **** **  **    *** ** *  * *
    *  *  * *******    * *** * * *  
 **** *** * *    ***  ** ** 
 * *      * *     * * *   ****  * ** ***    *  ***    ***  * * * ***   * ** of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
* **** ** **  * *    *   * *  * * **  **  ******  ****  *   ***  * * ****  = x2 = %.2f",x1);
   *  **** * * *  *******  *** 
****** *** ***  *   ******* *  * if(D>0)
*** *  ***** * **  *  **   **
 *   * **** *  *   * ***          **********   * * **     ** * *** *** ***   * of %.2fx^2 + %.2fx + %.2f = 0 are complex and   *    ***  * ***  
** * * *  *   *  ** ***    * * *   **        **   ** *    ***  * * = %.2f\n",x1);
 *** *   * *  **  * *  *    * **  * * *  *** *  * *     *   * ****** = %.2f",x2);
*    * **    ******  * ** * 
* *  *  **  **** **   * ** * **  if(D<0)
 *** * *  ***  ***  *** ** * * 
  * * *  **  *    *   ***** *    *** *** *    **** ** ** *  *   * of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
  **   **  * *    ** *** *  **  **  **  *** *  -b/(2*a);
    *  * ** *** * *      ********  ****  ** ** *   * *  * **  ****  *****   *
*** ** ** ****  * *      **** *  *     *   * ****  * **** *  ***  = %.2f+%.2fi\n",r,i);
      ****   *  * *****  *  ** *  *   *** ***  ** * *** * * = %.2f-%.2fi",r,i);
    *   * * **** *** *       *
}

Comments

prog.c: In function 'main':
prog.c:8:12: warning: implicit declaration of function 'sqrt' [-Wimplicit-function-declaration]
     x1=(-b+sqrt(D))/(2*a);
            ^~~~
prog.c:8:12: warning: incompatible implicit declaration of built-in function 'sqrt'
prog.c:8:12: note: include '<math.h>' or provide a declaration of 'sqrt'

Answer 6

Hidden content!
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main()
{
*** * *** * * *  ** *** * * a,b,c,d,x1,x2;
*** **  * *    *   * *  **  ****  *** ***  **     *** *  ***   ***  *
 *** **     ***  ***  *   * * *** **   
 ** ***** *   * **  ***** ****    * * * **   **
 *     **   ***      ** * *  * *** *   ** *
   *    ****  **       **   *
 ****   ****  **  **   * **
* **  ***** **  ** *  *  * ** **** **     ** ** * ***  *  * *** **  * ** * *  * of %.2fx^2 + %.2fx + %.2f = 0 are real and   *  **  *    *  **
  ****   *** * * ** ***  *  * *****  *** * ********     ** * *  *  = %.2f\n",x1);
   ****   ** ****  ** ****  *  *** *  * * *  *** * *  *  *  *** *    **   = %.2f",x2);
  ** ***** ** ******      *
** ** * *  ** *** ** ***** **  * * if(d==0)
 **** *****  * ** ** **  ** * 
*   * *    ** *  **  *  **   *  * **  * ** * *  ***     * * *       of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
  ** **** *** *   * ****  **       ** ** *  *** ***  ** *   ** *   ** = x2 = %.2f",x1);
  *** *** ***** *  * 
 *  * **    * ** * * * ** * 
 *** ****  **    *  * **    **
** *   **   * *   ** *   * * *   **  * * **      ***  *   ** ******** * * ****   of %.2fx^2 + %.2fx + %.2f = 0 are complex and  * *** **  ** ** * 
* ** *  ** *   *  *    **  * ** * * **    * *** *****  *  *  ** *  =  * ** *  **    **     * * * ** * 
  * * ** * ***  *  * ** *  *  *** *****  ******   **  * *  *   ** =  **   * **  ** *** *     **  * 
 ***** *      * ** ***  *  * * 
* **  *  **  **  ****     *  **     0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 7

Hidden content!
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
* **   **** ** *** * ** * *   a,b,c,d,x1,x2;
*  *** *****   * *     ***   * ******* **    *  ** *  ** ** **  **  ** *  *
* * **    *** * * * ** **  *  *  * *  
 *  *  ****  * **** * *  * = (-b + sqrt(d))/(2*a);
* * **   * **** * ***   *     = (-b - sqrt(d))/(2*a);
****   ***  *  **  *  ***** *  
**  * ****      *  * * * * ** * ***  *  **    *** *        **  *  * **    of %.2fx^2 + %.2fx + %.2f = 0 are real and different\n",a,b,c);
  * *** * ** * * **  * ** *  ***  * **    *  *******   * ** ** ** *   ***   ****** ***  *** ****   ** ** *** * * *  ******** **  ** * ****  *  **    **   **** * *   * *  ***  * *** *****  * **   *  **  ** *     *  ******** = %.2f\n",x1);
**** *** * *  *    ***    * * * ** ****    **  *   * * **  * **    *****   *** ** * ** ** * *** **  **** *   ** ********* *   * *** ** **** ** ** **   * * * *  *   * ** **   * ****  ** **  * * ** *     *  ***  ***   *  * * *    * = %.2f",x2);}
 *   **     *    *** ** ** **   if(d==0)
  **** *   ***  *   ***  ** *** * * ******** *   * * 
*** *   *  * **** *  ** ****   * * *  * ***    ***  *  *    *   **  ***  ** **      * ** **  of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
***** * ***      ** ***   * * *** ****    *****  * ** ** ** *  ****    ***** ***** **** ** **** ***  * ** * ** ** ******  *   * * ***      ** ** * = x2 = %.2f",x1);}
*** *      ***  * **  * * 
**** ***** * *  **     *** *  *  * **** *  *   ** * *   **    * *     of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
    **  *   *    **  * *  *   *********  *** ***     ** **** *** = **  ***    **  *   **  * 
 **** ****** *   *  *** * ***        **   * ***** **     * *   * =      *****   * *****  * * * * *
      * ****  **    *** *    * 0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 8

Hidden content!
#include  * **  * *  *
#include   ** ** * *

int main()

{
 *** ****  ****  *  **    *****  *  *** *** *   * 
 ***      * ** * *  **  *   *** * * **** * %f  ******* *   * * * *  *

  * * ***   * * * ****    ****
 *  * * **  ***  *****   * **   + sqrt(D))/(2*a);
* **** ** *   * *** **   * *   **    - **   ** ** 
 ** ** *******   * * ***   * * *  ***
  *  ***    ****    ** *** * **  *  *

  *  *    *   *    ** **    * (D==0)
* ** **** ** * ** ** ** * 
   **  ***  *  *  *  **  * **  **  * *  **  * *      * **** ** *****  *** * * *** of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 =      ** *     *  
* *  *     * **** ** 
 *   ** ***  *** * *      if (D>0)
*  **  **  ****   ******  * 
  * ******  *  *** ******     *     * **    ***  *  *** ** **** of %.2fx^2 + %.2fx + %.2f = 0 are real and different\nx1 = %.2f\nx2 =  * ** *   *  ** * *
 ** ** *    *     * * **   
** * ** ***  *  ***** *    **
  *** ** ** ******  *  
** *   *  ***    *     *    *   ** * *   ** * *      * * *  * * *   of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\nx1 = %.2f+%.2fi\nx2 = ** *  *** * ******   ****  
*** ** * **** *   * ******

 * *    **   *  * *  *** * * *  0;

}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 9

Hidden content!
#include * **   * ***** 
#include **  *  *** 
int main(void)
{
float a,b,c, D, x1, x2,i;
 * ***    **      ** *  * ** ** **  %f  *** * *    &a, &b, &c);
 **  * *  **   *  * *  ** * *  * 
 * ***  * * ******   **  *   (D>0)
   *   ** *  **   * **
* ** * *      ** ** *** * **  **** **  **  ****  *** * ** *   
** ** ****  * * * ***     *  * * **** ** *   *  ** *  *  *   **  **   *

* **** *  * *   *****       *** *  *   ** ** * * ****   * * ** *    *         * *** of %.2fx^2 + %.2fx + %.2f = 0 are real and  *   *   = %.2f\nx2 =   ** *** * *    * 
  * **     *      *** ****
 * ** ** **  * *  ** *  **   * if (D==0)
*  *      *    **** *  ** ***  *
 *  **  ** * ** **  * **  ***  ****   * **** *   *  *****   *
*  **  ** **** *  *** ***  *   * ***** *  ***  *       ** * ** *** * **  of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = *****     *  *
 *    *    *   ** **** *  *
   * ** ****    **** * * * * 
  ***** ****  * ***  * * * ***
  ** *  **     *  ** *   * *  **     x1=x2 = -b/(2*a);
**** *   ***  * * * * * ***** * *** *  *   * ** ***      * *** *   *
 *      * *   ** * * *  *****  *** ** *** * *       ******  **   of %.2fx^2 + %.2fx + %.2f = 0 are complex and  ***    =      *   =  * **** **** *** * *  x2,i);
     *    *   *  ** *  * *



* * *   ***    ** **   ***   *    0;
}

Comments

prog.c: In function 'main':
prog.c:10:16: warning: implicit declaration of function 'sqrt' [-Wimplicit-function-declaration]
         x1=(-b+sqrt(D))/(2*a);
                ^~~~
prog.c:10:16: warning: incompatible implicit declaration of built-in function 'sqrt'
prog.c:10:16: note: include '<math.h>' or provide a declaration of 'sqrt'

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output

---

prog.c: In function 'main':
prog.c:21:5: error: expected ';' before '{' token
     {
     ^

---

Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 10

Hidden content!
#include **   *  *      ** 
#include   ****  **

int main()
{
 * *    *      ****** ****     a, b, c,    ***** * x1,x2, realPart,      *     *


 *  * * * *      *  **** *   *   *   *  *** %lf * * ** * **** * *  &b, &c);


**** *    *  *    *** * ** ******* = b*b-4*a*c;

   **  *   **  *  *   ** **     condition for real and different roots


 ** *  *  *  *** *  *  *  *  * for real and equal roots
* **  ** ***  ***** * *  *   ***   (determinant == 0)
 * * * ***  *** *  ** **  ** **
 **    *   *   ***** *   * * * *  **    * **       = x2 = -b/(2*a);
 * **** * * **     *** * * * ** ***     ****** ** ****   *** **  of %.2fx^2 + %.2fx + %.2f = 0 are real and  ** ***  a,b,c);
   * * *    *****  *** ****** * *  *** * *   *  *   *  *      *  *  = x2 = *    *  x1);
 ****  *    *  ** * **** ****

** ***  ****  *****   *   * ** *  if (determinant > 0)
    *  *  ***   **     *    *
* * *  ***    **  * **   **** sqrt() function returns square root
 ****  **   * *** ***  *  ***   *  ****** *    * * **    = *   *** ***** ** ** *
** **   **  * **   *   **  *    *  *** *  ***** ** *** = **  * ****  *    

*     *  *    *  ***       **** *   ****    ** *  ***  ***  ** **    *    of %.2fx^2 + %.2fx + %.2f = 0 are real and  *** * *  *   *   *   
 **    **** ****  ** ***      ***   ** * ****** * * *   =       **** *  x1);
    **** **    ** ***      *** *** ** ** *  *** *    **     =  ***  * * x2);
   * * *   *   *  ** *     *   * if roots are not real
**  *** ** ** * * *   * *  **  **
 ** * ** *  ** * ** ***** *   
   *  **  ** *** *  **  * *  ***   *  * *  * *****   *** * *** = -b/(2*a);
   * * * * ** *  *  **  ****  ** ***** * ** *   * **   * *   =   *   **  *   **  *
*  * ***  * * **  *** * ** *   *  ** ** * * * **  * **** **  *    * of %.2fx^2 + %.2fx + %.2f = 0 are complex and *  *     **  *   * a,b,c);
** *   *   **   ***  **  ** **** * *** *   **** *  * **     ***  =    ****** * * *   realPart,   **   ***  *
   *      *   ***  *  ** **     **  *  *   *  *   * * ** * * ** *   =  ** **   * ***   realPart, * **** ******
** * * * *  * *  *  *   ** * **    

*** **   * **  *   **   **** * * 0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output