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

0 like 1 dislike
11.6k 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 | 11.6k 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:104.23.190.140
©2016-2025

No related questions found

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