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

0 like 1 dislike
16.9k views

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
[Exercise] Coding (C) - asked in Chapter 5: Selection Statements by (5.2k points)
ID: 28934 - Available when: 2017-10-26 18:00 - Due to: Unlimited
reopened by | 16.9k views
0 0
We will continue this question in few days
commented by (12.1k points)
0 0
Everything is fixed. Enjoy your time with The Judge :)
commented by (12.1k points)
0 0
ANNNNNNNNNNNNNNNNNNNNNNNNNNGRYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
commented by (-249 points)
0 0
Your code has newline at the end sometime. You learned this lesson many times!
commented by (12.1k points)
0 0
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.
commented by (-214 points)
0 0
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
commented by (9.9k points)

56 Answers

0 like 0 dislike 
Hidden content!
  *** *** *** ** *   
*     *  **** *****

int main() {
 ***       **  ***     * * *  *  *** ***
     **  * * ****   * *    * **  * * * *  %f  *  *    &a, &b, ** * ****
 *** *******   *** ***   ** **** ****
**   * ***    * * * ** **  ***   * {
* **** **** ***  ****     ** **  * ** *   *** *   ****  * *  * ***  ***  * of %.2fx^2 + %.2fx + %.2f = 0 are complex and  * *  *   =    *  **** =   ***  **   * a, b, c, (-b)/(2*a),    * *  *  * (-b)/(2*a), *** * * *** 
   *     *** * ** ** **  ** 
 *       *     ***  * ** *   if(d==0) {
  *   ** * *****   * ****   * *** *  * **    * * * *** *** *  **  * 
*** ******* * *  * * ** **  ** * *   ** **** ***  * ** ***    ** ******* of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 =  ****** ***  a, b, c, x1);
*   ***     ***     *  **
 * *** ** ** *  ** ****** ** *  *   *   * * {
 *   *   ****   ** ** ***  *** *****   ***   * * *  **** * ***   
*     * ***  *   * * **    * *        * **** * **** *   * *
*  * *  **** *   ** *    **   **  **   **  * *  ** * ****  * ** of %.2fx^2 + %.2fx + %.2f = 0 are real and * ** ** ** = %.2f\nx2 = **  * *  *  a, b, c, x1, x2);
 ** * ****** ** ** ***  *
}
answered
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
commented by (4.3k points)
0 like 0 dislike 
Hidden content!
#include *  * *   * ***  
 *      * * ***    
#include  ** * ******  *  

int main()
{
**** *  ****** *** *  ** * ***  *  ** * **
*****  **** *  **  * ***  *  ****    %f  **  *** *  ** *   *****   
******** ****  *  * ** * *   **  * * *** 
  *****    ***       **** **      **  ** 
*   ** * * ***  **   **  **   ****** **  ** *
 ** *** *  *   *  ** *   * *  *  * * 
     *  * * **** **   **** *  *  *    **  ** 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 =     *  * * *  ***  *
 * *   *  ***   * **  *****
**  ** **  ** *** *  *     * ***    ** * *  *** ** of %.2fx^2 + %.2fx + %.2f = 0 are complex and    **   **  =     * * *  = ****  *  **  * ** *  *    ** *  **   ** ** ** *** ***** *
***  **  *   *   * ***  ****** 0;
}
answered by (-498 points)
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
commented by (4.3k points)
0 like 0 dislike 
Hidden content!
#include ** *  **  *  * *
  * ** *   *  *  * * *   
* * ** * *  ** *   *

int main()
{
*   *   * * *** ******  *  * * *   *      ***  *
***   * * ***** * *   * * *   *  * ** *    * %f ** * *  ** * ** *** ****  ** *
***   **  * * *   * ****  ** *  *
*** * ** * ****       **    **   *  *    
  **  ***  **   ** * *   ***    *****
*         *   **     ** *   **         *
 ** ******  ** * * *    *  * ***  *   *   of %.2fx^2 + %.2fx + %.2f = 0 are real and ***** *    = %.2f\nx2 = ***    **    ***   *
 **   ** *  * * *      **** * ** 
**   ** * ** *   * *  *  * * ****  ***  **  of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = *  * **  *    *  *  
 ** ****   * ** *******     *   *
* * *   * *    ** * * * *  * *** **  ** * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and *     **   = %.2f + **  = %.2f -  *   ****  ******  * **  * * ** *    * ** ****** **   
**** *       ** * ** *** *    *  **   0;
}
answered by (-498 points)
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output
commented by (4.3k points)
0 like 0 dislike 
Hidden content!
#include <stdio.h>
#include <stdlib.h>
#include<math.h>
int main()
{
       * * *  ** *    ** *  a,b,c,x1,x2,D;
********* ***   *  *  ******* *   *      *** %f *** * * ** ** *  * **** *   *   *  
** * *         *** *     ** * **** * 
***  * *  * **** *** *** * * = (-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;
}
answered by (-258 points)
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
commented by (4.3k points)
0 like 0 dislike 
Hidden content!
#include <stdio.h>
#include <stdlib.h>
#include<math.h>
int main()
{
 **  ***  * **   * ****  *  * a,b,c,x1,x2,D;
 *  * *  ***  *** * * * * **   * *  * *  %f **  **   **         * **** ***    *
***  *** * ***   * * * *   ***  * 
**     * ***         * *  ** **  = (-b + sqrt(D))/(2*a);
  *  *** * * *  **    ****  = (-b - sqrt(D))/(2*a);
**     ** *  ****** *    * * *  
 *** **         *** * *  *** ******** *       *** * 
*** ** **   *        * *  **** **  *     * * *  ********** * ***** *  *   ****** **** ** ** *  of %.2fx^2 + %.2fx + 1.00 = 0 are real and different\n",a,b,c);
* * * ** *  *** **  *** ** ****  *   ***   ** *  * *   * *  *       ** *** **  *  * *  = %.2f\n",x1);
******  ***  * * **** **** *  *     * *   ***    *  *  * * ** ***   * * *     * * *   * *  = %.2f",x2);
***   *   ** *** **** *** ***  *** *   ** *   ** * *** *** 
 ** **   **  * *  ***     if(D==0)
******* * **** *   *  *****    **  * **  * ** * **
* ****  * *  * * *  **** ** * * ***  *  *** ***   ** **  *****  ** *  *    *  * *  *  * *    of %.2fx^2 + %.2fx + 1.00 = 0 are real and same\n",a,b,c);
*  * *  **  *        ** *  **  * * * * * **  **  * ****** * ***     ** * * ***     **** **** *   *  * *   = x2 = %.2f",x1);
**     **     ** * ** * ***  *  ****  ** ** *  * * *
    ** *   ***   * * * *  *** *    
*    **   ** * * *  *** * ** * * **** * *   ***   **   *   *** *
*    ** ***** ***   * *  **    * ****** * **** * *****    **** *** **   *      * ** **  of %.2fx^2 + %.2fx + 1.00 = 0 are complex and different\n",a,b,c);
*     * ** *    *  ** *  ***   *      *    * ****  * * * * ** ****  * *** * *** ***  ** ** *   = * * **      *   *   * **
   *   *   ******   *  ***  * ** * ** ** * *  * * *  * *** *** ****  ** **  *   ***** *   **   * * =   ** ***** *** * *  ***  * **
 ****  ***  **** ** * **** ******** ** * ** * *   ****  * 
  ***   ** ** *****     **     0;
}
answered by (-258 points)
0 0
prog.c: In function 'main':
prog.c:13:20: warning: too many arguments for format [-Wformat-extra-args]
             printf("Roots of %.2fx^2 + %.2fx + 1.00 = 0 are real and different\n",a,b,c);
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:19:20: warning: too many arguments for format [-Wformat-extra-args]
             printf("Roots of %.2fx^2 + %.2fx + 1.00 = 0 are real and same\n",a,b,c);
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:24:20: warning: too many arguments for format [-Wformat-extra-args]
             printf("Roots of %.2fx^2 + %.2fx + 1.00 = 0 are complex and different\n",a,b,c);
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commented by (4.3k points)
0 like 0 dislike 
Hidden content!
 *   *  ***** * * ** 
 ***  *** *   **** * * ** 
int main()
{
      *   *  ******  **   a,b,c,D = 0,x1 = 0,x2 = 0;
*  * * *    **    ***  ***     *** * ** ** * *      * ** **       *

* *    * **   * *  ******   *    ***** * of %.2fx^2 + %.2fx +%.2f = 0 * *    *   ** *  
 *   *    **   **  * * *      = (b*b-4*a*c);
 *   *  **  *  ********     (D < 0)
* *** ** **   * **   **    **
* * **   ** **** **   ****   * ***** * complex and  **      **     *
 ****      * **  * ** **** *  ** *  **** * =   * ** *  ** ***  *    *** **** 
  *    ** **  ***** * ** ** * ***     =  * **  * ** **** * *** **   
** ** *****  ****   * *
*      **  **  * ** ******    (D > 0)
**  * *    **  * **      * *
**    *  **        ** *  *** *  *  real and *  * ***  * **
***     *  ** ** ** ** ******  * ****    ** =     * ***      + sqrt(D))/(2*a));
* * ** * ***  *  **** *  ******  * **   * **  = %.2f",(-b - sqrt(D))/(2*a));
** * ****  **   * ***  ** ** *
  ** *       **    ** ** *     (D == 0)
 **  ***  *  ** *  **   * *  *
  *** *  *  * **  *  *****  ** *       **     real and same\n");
* **   **  ***  * ** ****   ****  * * = x2 = %.2f",(-b + sqrt(D))/(2*a));
   ****** *     * * ** **  
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
0 0
your output lack of 1 space at line 8 when print out "Roots of ..."
commented by (9.9k points)
0 like 0 dislike 
Hidden content!
*  * *     ** * *  
    ****  * *** ***
int main()
{
***    ** **  ***  ** **  *** a,b,c,D = 0,x1 = 0,x2 = 0;
  ***   ** * * ** * ***  * **** *    ** **** *    *   ***** *  ** * * *

 *   * ***** * * * *  *   * * * ** of %.2fx^2 + %.2fx +%.2f = 0 *** *  * **    *  
** *   * * *** * **   * = (b*b-4*a*c);
*    ***  *  **       ** (D < 0)
*****  **    * ****  *****
*     **    *** *  ** **** *    *** * complex and **** **  * *** 
  *   *    **  *** * *** * *    = ***       **  ** * **   ******     *
** * ** **  * * **   * ***       * **** *  =  * ***  *** *    * ** **** **  
*** *   *  *   * ** * **** *  
*** ***** *      ** *** * (D > 0)
 *    *** * * **** * * ******
  ****  *   ** *  * ****  *** ** *       real and *** * *  ****
*** * ** * **   *  *** ***** **********   * = * ***  *  ***  + sqrt(D))/(2*a));
* **   ** *** * ****    ***    ***  **  = %.2f",(-b - sqrt(D))/(2*a));
 *  *****  **  ****  ****
* *  ** **  *  ***  *          (D == 0)
* *   * ****   ****    * * *  *
*    **  *    ** *    ***** ******    ** * *  real and same\n");
***  ***  *    *    ***** * *  = x2 = %.2f",(-b + sqrt(D))/(2*a));
 *       ** *  **      ** *** 
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
0 like 0 dislike 
Hidden content!
        ** ** *       
     * *  **  * * **** 
int main()
{
*      ** *  * *** **   * *  a,b,c,D = 0,x1 = 0,x2 = 0;
********   **** **  *   * **  * ***  ***** * ** *   **  * * **  ***

********  **   *    ***    *** ** ** **     ***  of %.2fx^2 + %.2fx +%.2f = 0  ***  * **  
  ** *****   ***   *  *     = (b*b-4*a*c);
* ***********  *   **    * ** (D < 0)
* *   *  *  *  ***  **  *   
*    *  ** **  *** ******* * * ******** *** complex and ** * ******* *  
  ** **    *   * *** *   ***** *  *****  **** = * *  *      *   **   ****  *  **
******** ***** *  ****  * *   *   * ** =  *  *  *** *      * *** *   ****
 *  ** ** **  ** *      **** 
** *     *  ** **  *  *  * (D > 0)
**** **  ***     * **  ****
*** ** ** *  *    * **** ******* * ** * **  real and *  * * **   *   ***
*     *  **   **** *  **** * ** *     *   = * *   * **  ** * + sqrt(D))/(2*a));
* **** *   * *        *   ** *    = %.2f",(-b - sqrt(D))/(2*a));
   ** *    **** * *    ***
**   *   ** ****  *  ******  * (D == 0)
 **        *  *          
* * **** *    ****  **** *   *  * real and same\r\n");
 *   * ***    * **  *  *** ****** *     *  = x2 = %.2f",(-b + sqrt(D))/(2*a));
    *  * *    * ** ** ** **
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
0 like 0 dislike 
Hidden content!
* * *** ** ** * ***  ****
* * * *** *   * ** 
int main()
{
 * ****  *  *   **** ** **    * * * a,b,c,D = 0,x1 = 0,x2 = 0;
  *  * * ** *  * *    *  **   *   * **   * ***    * * ****   **   ** * 

** **** *  * *       *   * **   *     **** ** of %.2fx^2 + %.2fx +%.2f = 0 * ***  *** * 
 *****  *        *** * ****  = (b*b-4*a*c);
  **   *        * * ******  *** * (D < 0)
 * **   ** * *  ******* *  
  *** *  ****       *** ** *  *  *  complex and  *****   **   **
   ******  * **  *   * * * * *   *  *** **  =       * *    * ***  ** *   * *** * 
    * *****   * *    * *  ** ****  ****  = *     *  **  *   **  * **** 
 ** * *     * **     * * 
**** *    *** ** * ***   **** (D > 0)
** * * * * *   ** * * * *   * 
        * *  **  * * *** **** ****** **** * real and *  *  ** ** **  * 
 * **   *   *  *     *      * **  ** *  ** = *        *****  + sqrt(D))/(2*a));
***  *** * * **    * ***  * * **   *   = %.2f",(-b - sqrt(D))/(2*a));
 ** *****      ***  ****    *
    * *** **     * * *  ** **** (D == 0)
****** ** *   *   **  * **** 
**** * **    ****** * ****** ** **** *** real and same\r\n");
*    * *** * ****** ** **  * ** * * ****** = x2 = %.2f",(-b + sqrt(D))/(2*a));
   *  ** *    * * * **  * **
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
0 like 0 dislike 
Hidden content!
* * ** ****   * ***   
*    *  **** *    **** * 
int main()
{
 **    * *     *** * ***** **  a,b,c,D = 0,x1 = 0,x2 = 0;
**   ** ** *** * * * *** *  * **   **  **** ***      ****   ** **   **

****  * * ***   ***  * ****     * *** ***** * of %.2fx^2 + %.2fx +%.2f = 0 are",a,b,c);
 **  ** ******  * * ****  *** = (b*b-4*a*c);
    **   ** *   * *   *   *** *    = (-b + sqrt(D))/(2*a);
 ** *  ** * *   *****  ***** ** *   = (-b - sqrt(D))/(2*a);
**      **    ****    * ***** (D < 0)
 ******  **  *   ** * * * *
 ***** *  ** * *        ** * *    * *  **  **  complex and **** **      *   ***
* * ** ** * *** **  **  *** * *** ****  =     *******  ** ****  *  *    
 * ***    *  * *  *   **** ***  *** ***  = **** * *** * * *  * * **** * *   
****  *   **  *** ** *** ** **
     *   ***      * * ** (D > 0)
*  ** *  *  **  *  * **** ***
  **  * *** *  * *  *******   * ** ***  real and *********  *    
 *** * **  ***    * * ****  * ** **  ** *   *** = *  * ****    **** *   
 *   ****   **  * ** ** ** **   *  *  = %.2f",x2);
***  *   **  ** *   **  *   *
*  ***  ***        * *  *   (D == 0)
    *** *   * ** ****  *   
* ** ** ** *    * ****   ** *    * **  real and same\r\n");
*  * ** ** ** * * ****  ***   ******** ****   = x2 = %.2f",x1);
 ***** ** * *  *** **  * * *****
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
Page:
Welcome to Peer-Interaction Programming Learning System (PIPLS) LTLab, National DongHwa University
English 中文 Tiếng Việt
IP:162.159.115.31
©2016-2026

No related questions found

12,783 questions
183,442 answers
172,219 comments
4,824 users