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

0 like 1 dislike
8.6k 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 | 8.6k 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:172.70.178.72
©2016-2025

No related questions found

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