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

0 like 1 dislike
13.1k 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 | 13.1k 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     ** *  *    * ***       **** 
 * * * **  *  **   **      = (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 complex and   *        **   ** ** 
     ** *** **  *   * * *  *  ***  * *** * * * *   *  **   *** * ** *   = -%.2f+%.2fi\n", realPart,imaginaryPart);
 *** * ***    **   *  * *  *    ***** *   *   *   *   *** ***   * *  = -%.2f+%.2fi", *  *     *    
** ********* *  ** *  * *** * 
  * **** * **  * * ********    if(D == 0)
** * * ****   *    ** * ***

* *** **  ***  **   * ** ** **  *  *    *      * *   *   ****  **  *    of %.2fx^2 + %.2fx + %.2f = 0 are real and *** * * **   * 
* * * * **    ** *  *             *** *  **    *** ******   *** *   = x2 = %.2f", x1);
  ***  * ** *  * ****  *  * *
***  *    *   **  ****   *
** *   *   * ***  ***  * ** 
*  *    **  ******** *   ***** **  *  *  * **  * *****   * ** ** of %.2fx^2 + %.2fx + %.2f = 0 are real and     *** *  *   *
 ****** * *   ***   *  ** *    ** * **   **** * *  **  ** * * *  ** * = %.2f\n", x1);
  *  * ** ** *******  * *     *      * **   ***  * **  **  *  = %.2f", x2);
*  **   ** * *  ***   *    *
** **    *  * ****** *****  ** * *  ** 0;

}
answered by (-281 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
/tmp/ccgUqSsU.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x14c): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
commented by (4.3k points)
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
0 0
-----------Re-judge-----------
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 *  ** ***  * *
#include <math.h>
int main()
{
* *  ** *****    ** **  * *  * * *  a,b,c,x,y,d;
  ** *  *** * ***  * *     * ** *      %f   * *    *  ** *   * * *****
 *** * **     *  **  * ** ***   * ** *
* * *  * ***  *** * ** ** ** *
   *   *  ** * **  ****  * **  ****     *
   * * *   **   **  ** ***   (d>0){
  ** * ** ** *****  *** *  *  * ** ** ***  of %.2fx^2 + %.2fx + %.2f = 0 are real and * ******   *****   * 
 *** **  **  *** *  * **   *  *** **** = %.2f\nx2 = %.2f",x,y);
** ** ******  * ** ****
    ** *  * **   * ***     ***** if (d==0){
*** * *  ** * ** **** *** **  *** ** * of %.2fx^2 + %.2fx + %.2f = 0 are real and ***  * ** *  * **
* * * * ***     ***  *    ***** * * * = x2 = %.2f",x);
 * *   * * *   *  *  ** * * 
 * **  **   ***  ***   * *    
 *** *   *   ** *   ****** ****  
  ** ***  ** * * *****  ** ***  ***  ** * * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and ** *** ** *   **  
*  ** ** ** *       *  *** **** *** 
 *****  * ** * **      * *** ***  * *** =  ***   *  ** * *
*  *** **  **  * **   *     ** *  * *** =  *    ** **    
 *** *        * *** **** ****

  * *          **  * **   * *  *  0;
}
answered by (54 points)
0 0
/tmp/cc8k7Xv8.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x21f): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
commented by (4.3k points)
0 0
-----------Re-judge-----------
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!
#include   *  * **    ** 
* *  *   *       * ** 

int main()
{
*    * ** *  ***  *  *** ** **** a, b, c, D,            realPart, *  **   

 ** *  ****  *   *   *   ***     *     %lf * ** *  * * *   *** * * * ** *

* ***  **     ***  *   ***  ***** = ** *  

   * * **  *    ** * * *** (D > 0)
*   **    * * ** *  ****  **
 * ** * *    ** **** *      * **  *** *** * ** * ******    = **  **      **
  *    ** *** * ***      *   *  *** ***** *** ** *     *    =  * * ** *** *

 * *******      *    ** *  ***    * * **   *     * * ** *    *** **  * of %.2lfx^2 + %.2lfx + %.2lf = 0 are real and * * * *  = %.2lf\nx2 =   **  *  *  * * * *** b, c, root1, root2);

* **  * ****  **    * **    

*    * *** *  ** *  *  ***       if (D == 0)
****   ** ** * ****   * * ***
****   * **    ******* * *  * ***      *  *** *   ** *  ** = root2 = -b/(2*a);

*   ** * *** ****  ** *    * * *** **       **  *  ****   ***  of %.2lfx^2 + %.2lfx + %.2lf = 0 are real and same\nx1 = x2 = *  ** * * * a, b, c, root1);
   * * **  *  * **  * **** **

*  * *     ***  *** * ** ****
 ** * ** ** *** ** *   **     
* **  * ****   **      *    **     * * *  ** **  *** ***   = -b/(2*a);
    **    ** ** * * * *   ***   ** ****   *   * *  = *  * *** *

********* *     ***** *  *   *   ** ** ** * ** ****  **    *****  *    of %.2lfx^2 + %.2lfx + %.2lf = 0 are complex and * *  **    =     * **** =    *** *  *  *** a, b, c, realPart,   ** * **  realPart, **** * * 
**   ** ** ** * * *****   

  * ** ** ***   *  * ** ***   ****  ***  *** *   ** ***  * 
***     ** **   ** **  **    * 0;
}
answered by (5.2k points)
0 0
/tmp/ccibyL4w.o: In function `main':
prog.c:(.text+0x89): undefined reference to `sqrt'
prog.c:(.text+0xd4): undefined reference to `sqrt'
prog.c:(.text+0x1fc): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
commented by (4.3k points)
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
0 0
/tmp/ccfjcMIR.o: In function `main':
prog.c:(.text+0x89): undefined reference to `sqrt'
prog.c:(.text+0xd4): undefined reference to `sqrt'
prog.c:(.text+0x1fc): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
commented by (4.3k points)
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
0 0
-----------Re-judge-----------
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
commented by (4.3k points)
1 like 0 dislike 
Hidden content!
#include <stdio.h>
#include <math.h>

int main()

{
* ******  *   *  ** * * * ****   *   *****  *** **  *  **   

** *           **********   ***   * *  ** %2f  * *    *  * *   **    * **
        * * * * *  * *    *   = (b*b-4*a*c);
*   * **   *** ***    **** * *** = (-b + sqrt(D))/(2*a);
  ****  ***   ******** ** *  = (-b - sqrt(D))/(2*a);
***    *  * *   **   *  *** = -b/(2*a);
*  *  ***** ** * ** * * *   *  * ***   * =sqrt(-D)/(2*a);

***  **   * ***   * ** *  *   *  (D==0)
 *      **  *  ** * ** *** 
*** * *** *** *    ** **  *** *** **     *  *   *  ** * ****** * **   * ***  of %.2fx^2 + %.2fx + %.2f = 0 are real and   *   * **** *    
  ***  ****   ***  ** * *  *** ****      ** **    *    * ******* = x2 = %.2f",x);
 * ** *** * * ***   * **  * *   
**  **        * **     **** * if (D>0)
* * *    * *** *  ***    *
* *   **  **    ** ***   **  * * * ** * ******** *  *** *    * ** of %.2fx^2 + %.2fx + %.2f = 0 are real and ***    *******   
 *****  * * **** ** ****** *  ****  **   *  **      *  * **     ****   = %.2f\n",x);
** **  ***      * ** ** ** *                ** * ** * *   **   = %.2f",xx);
 *** ** * ** ******  *   **  
*    * *  * *  * ***       **     *
*  *    **** **   *** * **  
***   ** * * *** ***** **        ** *  ** * ** *** ***   ***** *** * *     of %.2fx^2 + %.2fx + %.2f = 0 are complex and  *  * * ***  * ****  
**   * **   ***** ***      * *  *****   * * ** ** **** *** *        * ** *  = *** **  * ** *     * *  **  ** * *
*   * *      *  ** * * * **   *****    *** ***   *  ***      * ** * =  **  *****  ***     * * * ** 
 *  *    ** * ****  *  

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

}
answered by (-249 points)
0 0
/tmp/ccwpNp77.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x13e): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
commented by (4.3k points)
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
0 0
/tmp/ccWys99e.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x13e): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
commented by (4.3k points)
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
commented by (4.3k points)
0 0
-----------Re-judge-----------
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
commented by (4.3k points)
1 like 0 dislike 
Hidden content!
*  **  **  * *  *   ****
 *  **  * * * * * 
int main(){
* ***     ** * ****   *   a,b,c;
 *    ***    ** * **  * ***   ****    D;
*  *   *  * ***    *   * *  **   ***  *** %lf  *        * *****    * ** 
* *    ** *  * **   * **  * * *  - 4*a*c ;

 **      *  * *  * ****  ****  *  **  * **    of %.2fx^2 + %.2fx + %.2f = 0 * * ** ** *  *

    *** *       * **** *** *** * ***** ***
 *    ***  *  * ** *   ******  **  * ** ** ***   * * ***  *  * * * ****** * complex and *     * * ** * ***
 * **** *    *** **** ****  **  * *  *   ** **    **  *  **    *** *  = ** *** * ** * *   (-b) / (2*a) ), sqrt(-D) / (2*a) );
  *  **   * *     *    *  **  *  * * ******    * *     ** **  ****      *  = *   **  ***** (-b) / (2*a) ), sqrt(-D) / (2*a) );
* ** ** *  ***  **** *   
*** * *  *    *  ****  ****** * if(D==0){
* *     * *  ***  * *  **  * **** ** **       **** * * *      real and same\n");
**  *  *    * ** **  *** *       *  * *  ***     ** *    *** = x2 = %.2f",( (-b) / (2*a) ) );
** ** **  **   *** * **
*   * * ***** **** *  *     ***  *    
  **** *  **    **    ** * **  *  * * ***  **    **  ******  **   real and ** *** ** *  * * 
     *  *** * * **** **  ** **  *** ***** * * * **  * * *  * = %.2f\n",( ((-b) + sqrt(D)) / (2*a) ) );
 **   ***     ****  **** **  ***  ** * ** **** **** ** *** **   * = %.2f", ( ((-b) - sqrt(D)) / (2*a) ) );
* **** * **   * ***  * *   

*** * **** *    *   *****  *    0;
}
answered by (-116 points)
0 0
/tmp/ccpv8G38.o: In function `main':
prog.c:(.text+0x51): undefined reference to `pow'
prog.c:(.text+0xdd): undefined reference to `sqrt'
prog.c:(.text+0x13f): undefined reference to `sqrt'
prog.c:(.text+0x213): undefined reference to `sqrt'
prog.c:(.text+0x26a): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
commented by (4.3k points)
0 0
-----------Re-judge-----------
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!
#include <stdio.h>
#include <math.h>

int main()

{
  ***  *   ***   * *  *****    *    *** **   *   ****  

**     **** *  *      *     *    **       * *  %2f ****    *** * ** * *   *** **   * 
* ***** ** * **** * *   *  * * ** = (b*b-4*a*c);
          ** ** *  ***   * = (-b + sqrt(D))/(2*a);
 **  *  *  * * *    ** **       = (-b - sqrt(D))/(2*a);
 *  * * * *** *  * ** * * * *  * = -b/(2*a);
* *   * ** **  * * **** * ***  *  =sqrt(-D)/(2*a);

*   *  * * * *******  (D==0)
    *    ** **  ***  **  
     *  * ****  ****** *    *   *   *  *    * *********  *** *** *    *** of %.2fx^2 + %.2fx + %.2f = 0 are real and ******** * ****** *
  *** ** * * ** * *  *** ** ** *** * *** ** ***  * *  *   ****  = x2 = %.2f",x);
*********** *  *      * * *
  ** * **  *** * **  ****** **    * if (D>0)
 ***         *   **** * *  
***   **** * ****   *    *  ******  * * *** **   ****** * * *** *  of %.2fx^2 + %.2fx + %.2f = 0 are real and *  ** ** ***  ******  
  **** ** *   *****  **** ** *  **** **   *   ********  **        ***  *   *** * = %.2f\n",x);
* ***  *** **  **  ****    *     *   * ** *  ** *   ** ***** * ** = %.2f",xx);
  **  * *  **  * *   ** *** * *
*  *   *  ***  *  *  **  ** *  *  
 ** *  *   *   ***     **
 *  *   *  *  *** **   ** ******  *  **    **** *  *  *****  *   *   *    *   of %.2fx^2 + %.2fx + %.2f = 0 are complex and *** ***   ****  **** 
   ** * ** ***  * *    * **   ** *** ***  * **  ****  * * *  * * =  **  **  **  *****  * **  * ** **  * *
 * **  * *     ******   *  ***  * **  ** ** ** * ** **  *  = * ** *   ** **** *  ***   *  
* * ***  *   ***   **   *

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

}
answered by (-249 points)
0 0
/tmp/cckgLAYq.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x13e): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
commented by (4.3k points)
Page:
Welcome to Peer-Interaction Programming Learning System (PIPLS) LTLab, National DongHwa University
English 中文 Tiếng Việt
IP:162.158.158.227
©2016-2025

No related questions found

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