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

0 like 1 dislike
13.3k 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 | 13.3k 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:172.71.255.49
©2016-2025

No related questions found

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