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

0 like 1 dislike
11.9k 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 | 11.9k 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:172.69.130.52
©2016-2025

No related questions found

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