0 like 1 dislike
14.8k 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 | 14.8k 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:172.69.17.58
©2016-2025

No related questions found

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