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

0 like 1 dislike
8.6k 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 | 8.6k 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:172.71.254.197
©2016-2025

No related questions found

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