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

0 like 1 dislike
2.4k 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 | 2.4k 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:172.70.178.231
©2016-2024

No related questions found

12,783 questions
183,443 answers
172,219 comments
4,824 users