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

0 like 1 dislike
9.2k 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 | 9.2k 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:172.70.100.185
©2016-2025

No related questions found

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