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

0 like 1 dislike
12.3k 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 | 12.3k 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:172.70.111.110
©2016-2025

No related questions found

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