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:172.71.254.103
©2016-2025

No related questions found

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