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

0 like 1 dislike
9.4k 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 | 9.4k 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:172.70.126.116
©2016-2025

No related questions found

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