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

0 like 1 dislike
7.6k 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 | 7.6k 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:108.162.216.74
©2016-2025

No related questions found

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