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

0 like 1 dislike
14.1k 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 | 14.1k 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:172.69.130.92
©2016-2025

No related questions found

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