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

0 like 1 dislike
9.6k 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 | 9.6k 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:172.69.59.114
©2016-2025

No related questions found

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