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

0 like 1 dislike
12.3k 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 | 12.3k 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:108.162.241.184
©2016-2025

No related questions found

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