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