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:172.69.130.71
©2016-2025

No related questions found

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