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

0 like 1 dislike
6.6k 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 | 6.6k 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:108.162.216.189
©2016-2025

No related questions found

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