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

0 like 1 dislike
13k 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 | 13k 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:172.70.80.20
©2016-2025

No related questions found

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