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

0 like 1 dislike
9.8k 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 | 9.8k 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:172.70.127.202
©2016-2025

No related questions found

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