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

0 like 1 dislike
7.9k 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 | 7.9k 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   *  * *  ***    *  *** **  *     
** *  * *  * * * **  * ** = (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:172.71.254.41
©2016-2025

No related questions found

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