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

0 like 1 dislike
9.1k 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 | 9.1k 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:172.70.130.207
©2016-2025

No related questions found

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