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

0 like 1 dislike
5.3k 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 | 5.3k 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:172.70.126.47
©2016-2024

No related questions found

12,783 questions
183,443 answers
172,219 comments
4,824 users