0 like 1 dislike
9.7k views

Write a program to find roots of a quadratic equation

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 | 9.7k views
0 0
We will continue this question in few days
0 0
Everything is fixed. Enjoy your time with The Judge :)
0 0
ANNNNNNNNNNNNNNNNNNNNNNNNNNGRYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
0 0
Your code has newline at the end sometime. You learned this lesson many times!
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.
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

56 Answers

0 like 0 dislike
Hidden content!
*** *** * * * **
** ** * * * *

int main() {
*** **** ***** ****** ** * * * ** * *
** * * * * **** ** *** ** ***** %f ** &a, &b, * *******
*** * ** ** * *** ***** *
* * ** * * *** * * ** * {
* * ****** * * ** **** ** * * ** * **** * * ***** * * * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and **** * = * * * ** = ** * * * a, b, c, (-b)/(2*a), ** *** ** (-b)/(2*a), * * *
* *** ***** * * **
*** **** * * ** * **** * if(d==0) {
* *** * * * * * * ** ******* **** * * *** ** ** **
* * * **** * * ** * *** * * * * * * * *** of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = * * * a, b, c, x1);
* **** *** ****** * *
** * * ** ** ** * *** *** {
* * * * * **** *** * * *** *** * * * ** ***** * *
* *** ***** * *** * ***** * **** **** ** * ** ** * * ** **
* * ** * ** * * * * * ** ** * ** * ***** ** ** * of %.2fx^2 + %.2fx + %.2f = 0 are real and **** = %.2f\nx2 = ** * * ** a, b, c, x1, x2);
** ** * ******* * * ** ** *
}
answered
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
0 like 0 dislike
Hidden content!
#include * * *** **
* ** ** ** ***
#include ** * * *

int main()
{
***** * * * ** * * **
** ** * * ** **** * ***** ****** ** ** %f **** * *** * * ** ** ******
******* * ********* * ** *** ***
* *** ** ** * *** * ** * *
** * ** *** * * ** * * * ** ** **
* *** ** ** ***** ** ** **
**** * ** * * * ****** ** *** ** *** * of %.2fx^2 + %.2fx + %.2f = 0 are real and ** *** * = %.2f\nx2 = ** * * ** **
* *** ** * * ** ** if(D==0)
* * ** * * ****** ***** *** of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = * ** * ***
* * * * *** ** * *** *
* * ** * * **** * ***** * * * * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and * **** = ** ** = ** * **** ***** **** * * * **
** ********** *** * * * *** 0;
}
answered by (-498 points)
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
0 like 0 dislike
Hidden content!
#include * * * ***
** * * * ** **
* * * * ** * ***

int main()
{
* ** ** * *** * ** * *
* * * **** * ** * * * * ** * * %f ** * ** * *** ****
** *** ** * * ** * **** **** * ***
***** ******* * * **
** * *** * * * * ** * **** *** * ***
***** * ** ** ** ** ** **
* **** * * * ** ** ** * * * *** * * * of %.2fx^2 + %.2fx + %.2f = 0 are real and * *** = %.2f\nx2 = ** ** ** ** **
* *** * **** * * * **
** * * * *** * *** * * * of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = * ***** * ** *
*** * * * ** * * * * * **
** * * * * ** **** * * * ** *** of %.2fx^2 + %.2fx + %.2f = 0 are complex and * *** ** = %.2f + * ** = %.2f - ** **** ** * * * ****** ** * * *
*** * * * *** * ** ** ** 0;
}
answered by (-498 points)
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output
0 like 0 dislike
Hidden content!
#include <stdio.h>
#include <stdlib.h>
#include<math.h>
int main()
{
* ** ***** *** * a,b,c,x1,x2,D;
* * * ** * ** ** ******** **** %f * *** ** **** ** * **
** ***** ******* *
*** ** ** **** * = (-b + sqrt(D))/(2*a);
** ** * **** * = (-b - sqrt(D))/(2*a);
**** ***** *** * * *
**** ** ***** ** * * *** ** ** * * *** * * * * ***
* *** * * * ***** ** * *** ** * *** ** ** ** ** * ** ** *** *** ***** * * *** ** of %.2fx^2 + %.2fx + %.2f = 0 are real and different\n",a,b,c);
** ** * * * **** * ** * ** ***** ** *** *** * * ** ** ** * *** * ** *** = %.2f\n",x1);
*** ** ** * * * * ** *** ** * * *** * ** * * * *** * **** * * = %.2f",x2);
* * ** *** ** ** * *** * * * * *
* * ** ** ** ** ** if(D==0)
* * * ** *** * * * ** ** * ***
** *** * ** ** * * ** * * * ** *** ** **** ** * *** **** * * * * ** * ** of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
* * *** ******* ** **** * **** ** *** ** ** *** * * *** * * * * * * ******* ** = x2 = %.2f",x1);
**** * *** *** * ** * ** * * ****** * ***** *
** *** * * ** **** *
** ** * * ** * * * ***** * ** *** * ** *
* **** * ** ****** * *** * * * ** ** ***** ** ** **** *** of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
* * * * *** ********* *** ***** * ** *** ** * * * **** ** * * ** = * * ** * * *** *
** *** * * ***** **** ** * **** *** ** *** *** ***** *** * ** *** ** * * = **** *** * *****
* * * * * * *** * ** * * **** * ***
* * ** * ** * *** * * * * 0;
}
answered by (-258 points)
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
0 like 0 dislike
Hidden content!
#include <stdio.h>
#include <stdlib.h>
#include<math.h>
int main()
{
** ** * * * * * ****** a,b,c,x1,x2,D;
** ** * *** * *** * ** * **** ** %f ** * *** ***** *** **** *
* *** ***** ***** ** *** *
***** *** * * * * ** * ** = (-b + sqrt(D))/(2*a);
* * *** * ** ** = (-b - sqrt(D))/(2*a);
** * * * * * * * * ** **
** * *** *** * * * ** **** *** **
** ** * * ** *** ** ** * * * ** * * ** * * ** ** * **** ** ** * of %.2fx^2 + %.2fx + 1.00 = 0 are real and different\n",a,b,c);
* * * * ** ***** *** * * * ** *** * * * * **** ************** * ** ** = %.2f\n",x1);
** *** ** * * ** ******** * * * * ** *** * * * * * * * * * * * * *** * ** ** = %.2f",x2);
* ** * *** * * **** * * * *** *
* * * * * * ******* if(D==0)
* * * * * *** ** * * *** ***** * ******** *
* ** ** ** ** ** ** ** ** ** *** ** * * * ** * * * * ** * * * * * ***** of %.2fx^2 + %.2fx + 1.00 = 0 are real and same\n",a,b,c);
* * * *** * * * * ** * ** * ***** ** * *** * * ** * * **** * ***** = x2 = %.2f",x1);
* * * * * *** *** * ** **** * ** * **
*** ** * ** ** * * ** ** ***
* * * ** * ** * * * * ******** *
* ** * * * * * * * * * * * * *** ** *** * * ** ** **** of %.2fx^2 + %.2fx + 1.00 = 0 are complex and different\n",a,b,c);
** ** * ** * * ********** *** * * * ******* *** *** ****** ** ** ** ** * * * = * *** * * * * * *
* **** *** * ** ** * *** ** * ** ** * * ** **** *** ** ** * *** ***** * * * = ** * * * * ******* ****
** ** * * **** ** * * * *********
* * * ** ****** ** * * 0;
}
answered by (-258 points)
0 0
prog.c: In function 'main':
prog.c:13:20: warning: too many arguments for format [-Wformat-extra-args]
             printf("Roots of %.2fx^2 + %.2fx + 1.00 = 0 are real and different\n",a,b,c);
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:19:20: warning: too many arguments for format [-Wformat-extra-args]
             printf("Roots of %.2fx^2 + %.2fx + 1.00 = 0 are real and same\n",a,b,c);
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:24:20: warning: too many arguments for format [-Wformat-extra-args]
             printf("Roots of %.2fx^2 + %.2fx + 1.00 = 0 are complex and different\n",a,b,c);
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0 like 0 dislike
Hidden content!
* * ** *** * **
*** **** ** *
int main()
{
********* * ** * *** ** a,b,c,D = 0,x1 = 0,x2 = 0;
**** ** * * * * **** * *** * **** * *** * * * ***

* * ** ** * * * ** *** ** ** of %.2fx^2 + %.2fx +%.2f = 0 * * ** *
** * * ** ***** ** ** ** *** = (b*b-4*a*c);
* * ** ************ * (D < 0)
*** *** ** * ****
**** **** ** ** ** * * ** * **** complex and * **** * ***
* ** **** * * * * * * *** * * = * ** * *** ** * ***** ** **
* * *** * * *** * *** * *** * * = ******** * ** ** * * **
*** * * * ** *****
** * ** **** ** *** (D > 0)
** ****** * ** ** ** *
** ** * * ** ****** real and * ***** *
* ** *** *** * * ***** **** * * = ** * ** * + sqrt(D))/(2*a));
** * * * * * **** * ** ** ** * = %.2f",(-b - sqrt(D))/(2*a));
** * * ** * * * * *** *
* * * ***** *** * (D == 0)
*** * * *
** ** * ** * **** * * ** ** real and same\n");
* ** ** * * * * * ** * ** ****** * = x2 = %.2f",(-b + sqrt(D))/(2*a));
** * * **** *** *****
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 0
your output lack of 1 space at line 8 when print out "Roots of ..."
0 like 0 dislike
Hidden content!
* * * ** ** *
** * ** * *****
int main()
{
* *** * **** ** * * * * * * a,b,c,D = 0,x1 = 0,x2 = 0;
** * * ** * *** ** * *** ** * *** *** * *** *** * **

* ** ** * * *** *** * * ** *** *** of %.2fx^2 + %.2fx +%.2f = 0 * *
* *** ** ** ** *** * ** **** = (b*b-4*a*c);
**** ** * * ** **** *** * (D < 0)
* ** * * * ****
***** ****** * **** * ***** * complex and *** *** *
** ** * *** ** * ** * = ** ** * * * * * *** *
***** * * * ***** * *** * **** = * * * * *** ** ** * *
*** ** * * *** ***** ** *
* *** * ** ***** * ******* (D > 0)
******** * * * **** ***
* *** ** * ** * **** ** *** **** real and **** * ** *****
* * * * **** * **** = ** *** * + sqrt(D))/(2*a));
* ******* *** ** * ** * ******** * *** = %.2f",(-b - sqrt(D))/(2*a));
** ** * * * * ***
* * ** * *** (D == 0)
* * * *** *** * * ** *
** * * *** ** ****** ** ** * real and same\n");
**** ** * * *** ***** * * ** * ** * = x2 = %.2f",(-b + sqrt(D))/(2*a));
* * * * ** * ***
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 like 0 dislike
Hidden content!
* * * *** ***
* ** * ******
int main()
{
* * * * * ** * ** a,b,c,D = 0,x1 = 0,x2 = 0;
** ** * ** ** ** ** ** * * * * ** * ** * ** * ** * *****

**** * * * * ** * ** * * of %.2fx^2 + %.2fx +%.2f = 0 ** ** * * ** *
** * * * * * * * * = (b*b-4*a*c);
** ** * ** ** ** * * * (D < 0)
* ** * *** * * ** ** *
* ***** ** * * *** * * **** * complex and * * ** ***
****** * *** * *** * * * * **** * *** = *** * ***** ***** ** * *
* * ** ** * * ** * * ** ** ** * = **** ** * * ** *** * * * ** *
**** * * ** ** ** ****
******* ****** * ***** * * (D > 0)
**** ***** ** * ** *
*** *** * * * * * * ** ** * real and ******** ** ***
* ** * ***** * * * ****** * * * = ** * *** * * + sqrt(D))/(2*a));
* ** *** *** * * ****** ** ******* * = %.2f",(-b - sqrt(D))/(2*a));
*** ** *** ** ** * *****
*** * *** * * ** * (D == 0)
** * ** *** * ** **** ** **
* * *** * * *** ** * *** *** * real and same\r\n");
*** *** *** * ** **** * *** * = x2 = %.2f",(-b + sqrt(D))/(2*a));
*** * * * ** * * ***
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 like 0 dislike
Hidden content!
*** ** * * ** ** **
* * * ***** *
int main()
{
**** * * * * * ** a,b,c,D = 0,x1 = 0,x2 = 0;
** ** * * ** * **** ** * ** **** * **** ** * ** * **

***** * ** *** **** ** * * ** * *** of %.2fx^2 + %.2fx +%.2f = 0 * ** * * **
* * * ***** * * * ***** * * = (b*b-4*a*c);
* * * ** *** (D < 0)
* **** ** ** ** * *
* ** *** **** *** * ** ** * *** complex and * * * * ** *** *
** ***** * * * ** * ** * *** * **** = ** ** * * ** * *** ** **
* * * ** * * ***** ** * * * * * * = * ******** ***** ********
** * * *** *** * * * *
* * * * * ***** (D > 0)
* * * * ** * **** *
** ** * * * ** * * *** * * ** * ****** real and ** * * *******
**** *** **** * * * ** **** * = * ** * ** * + sqrt(D))/(2*a));
*** * ** **** * * * *** ** = %.2f",(-b - sqrt(D))/(2*a));
** ****** ******* ***** * **
* *** * * ** * (D == 0)
* * * * * * ** ** *
* ****** **** ** * ** ** * ** real and same\r\n");
** * ** *** * ** ** * **** * ** = x2 = %.2f",(-b + sqrt(D))/(2*a));
** * * *** * ** * ** * * *
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 like 0 dislike
Hidden content!
* * * ** *** *
* ***** *
int main()
{
*** * * * ** ** *** *** ***** * a,b,c,D = 0,x1 = 0,x2 = 0;
* * * ** *** * * * ********* *** ** * * * * * ** * ** ** * *

* ****** ** * * **** * ***** ** * *** of %.2fx^2 + %.2fx +%.2f = 0 are",a,b,c);
* * * *** * * * * = (b*b-4*a*c);
* * ***** * * * = (-b + sqrt(D))/(2*a);
***** * ** ***** * = (-b - sqrt(D))/(2*a);
** ** **** ** * **** (D < 0)
***** * * * *
* * * * ** * * * * ****** ** * complex and *** * * * * *
*** ** ** * * *** **** = *** * * **** * ***
* ** * ** **** * * **** * ** = *** * *** * ** * ***
** ** *** ** ** **** **
***** ********** * ** (D > 0)
*** *** * ** *
* ** * * * * * * *** *** *** real and ** *** **** *
** * * ** ** ** ** * ** ** ** * = ** * * **
* * ** ****** ** * * * = %.2f",x2);
* *** **** ** * *
* **** * * *** * * ****** * * (D == 0)
*** ** **** * * * *
** * * ** ** **** * * * * * ** * real and same\r\n");
* *** **** * * *** ** * * * ** = x2 = %.2f",x1);
***** ** * ** * * * ****
}
answered by (-214 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
Welcome to Peer-Interaction Programming Learning System (PIPLS) LTLab, National DongHwa University
English 中文 Tiếng Việt
IP:172.69.58.242
©2016-2025

No related questions found

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