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

0 like 1 dislike
14.8k 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 | 14.8k 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:172.70.50.51
©2016-2025

No related questions found

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