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:172.70.131.161
©2016-2025

No related questions found

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