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

0 like 1 dislike
9.5k 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 | 9.5k 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:172.71.254.49
©2016-2025

No related questions found

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