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