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

0 like 1 dislike
12k 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 | 12k 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:172.69.59.82
©2016-2025

No related questions found

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