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

0 like 1 dislike
14.1k 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 | 14.1k 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:172.70.80.42
©2016-2025

No related questions found

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