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

0 like 1 dislike
14.8k 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 | 14.8k 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:108.162.241.33
©2016-2025

No related questions found

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