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

0 like 1 dislike
12k 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 | 12k 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:172.71.254.192
©2016-2025

No related questions found

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