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

0 like 1 dislike
12.2k 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 | 12.2k 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:172.69.6.173
©2016-2025

No related questions found

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