0 like 1 dislike
2.4k 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 | 2.4k 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!
#include <stdio.h>
***** * * *
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 real and ** * * **
* *** * *** ******* *** * * ** * * * **** * * ** * = %.2f\nx2 = %.2f",x1,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 ** * * ***
** *** * * ** * ** ** *** *** ******** ** = ** ** * ** * * * * * ** * *
* ** ** *** ***** * * * ** ***** * ***** * *** * * *** = **** * * * * *****
* ****** * ** ** * **
* * * * * * *** ** * ** * 0;
}
answered by (-281 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>
* * ** **** *
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 %.2f x^2 + %.2f x + %.2f = 0 are real and *** * * * ** **
* ** *** * * **** ** * ** * * ** * *********** ** = %.2f\nx2 = %.2f",x1,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 * * ** ** ** *
*** ***** * ** * * ** ** ** *** ** * ***** * * = * * ** * * ** * *
** * * * ** * * * ** * *** * * * * * *** * ** ** = ** * ** * * * ** * * * *
* *** ** ***** * *****
* ** * * * * ** ** * 0;
}
answered by (-281 points)
0 0
Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output
Case 3: Wrong output
0 like 0 dislike
Hidden content!
#include <stdio.h>
#include <stdlib.h>

int main()

{
* *** *** * * * * * * ** * a,b,c,x1,x2,D=0;
* * * * * *** ** * **
* *** * * * * **** * ** * * * %f * * ** * * ** ** * *** **
* ** *** * ** * *** ** **
** ** * ** ***** * **** **
* *** ** ***** * ** * + sqrt(D))/(2*a);
*** ** * * * ** ** * ** * - sqrt(D))/(2*a);
** * ** * * * * **
******* ** * *** ** ** * *
* ** ** * ****
** *** ******* * * ** * ** ** * *** ** * * ****** * * *** of %.2fx^2+%.2fx+%.2f=0 are complex and ** * * * * *** ****** ** *
*** * * * ***
* ******* * **** * *** *
* **** * ** * * ** * * ** if(D==0)
* ** * * * * ** * **** *
* * * * * * ** ******* * * * * * * of %.2fx^2+%.2fx+%.2f=0 are real and same\nx1=x2=%.2f",a,b,c,x1);
* *** ** * ** * *
* ** ** ** * * *** ** * **
* **** * * * **** *
**** ***** * *** ** ** * *
*** * * * ** * *** * * **** * *** ** **** * ** * *** of %.2fx^2+%.2fx+%.2f=0 are real and * ** **** * * * ** *
*** ** * * **** ** ** *
****** **** ****** ** * ** *
* ****** *** *** **
* *** * * ** ** * 0;
}
answered by (-127 points)
0 0
prog.c: In function 'main':
prog.c:12:14: warning: implicit declaration of function 'sqrt' [-Wimplicit-function-declaration]
     x1=(-b + sqrt(D))/(2*a);
              ^~~~
prog.c:12:14: warning: incompatible implicit declaration of built-in function 'sqrt'
prog.c:12:14: note: include '<math.h>' or provide a declaration of 'sqrt'
0 like 0 dislike
Hidden content!
* * **** ** * * *
int main()
{
* ** **** **** * *** * a,b,c,D;
*** ******* *** * * *** * * * * * x1,x2,r,i;
* *** ** * *** * ** * ** * * ** **** * * * *** ** ****
** ** * ** * ** ***** *** * * *
** ** * ** * ** * ** *** ** * *
***** ** * ***** * * * * *** ** *
* *** * *** * ** ***
* *** ** * ** * ** ****
* ** **** * **** * * * * * ******** * * * ***** * * of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
******** * ** ** * * * * * * * * *** * *** *** *** = x2 = %.2f",x1);
**** * * * *
** * ** ***** * if(D>0)
* *** * * ** * ***
* ***** * *** **** * *** *** * ***** * * * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and ***** * ***
*** ** * ** * **** * ** * ** ** * ** * ***** * * *** = %.2f\n",x1);
** **** *** * ***** ** ********** * * * * **** * * * = %.2f",x2);
* * ***** * ** *
* * * ** *** *** **** * * if(D<0)
**** * ** * * ** * * *
* * *** ** ** * **** ** *** *** *** * * * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
* **** ** * ** *** * *** * ** ** *** ** * -b/(2*a);
**** * * **** ** ** *** ** * ** * * * ***** **
* *** * ** ** * * * * *** *** * ** * ** *** * * * = %.2f+%.2fi\n",r,i);
**** *** * * * ** ** * * * ** * * * * * ** = %.2f-%.2fi",r,i);
* ** * ** ** ** ** ****
}
answered by (-329 points)
0 0
prog.c: In function 'main':
prog.c:6:5: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
     scanf("%f%f%f",&a,&b,&c);
     ^~~~~
prog.c:6:5: warning: incompatible implicit declaration of built-in function 'scanf'
prog.c:6:5: note: include '<stdio.h>' or provide a declaration of 'scanf'
prog.c:12:9: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
         printf("Roots of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
         ^~~~~~
prog.c:12:9: warning: incompatible implicit declaration of built-in function 'printf'
prog.c:12:9: note: include '<stdio.h>' or provide a declaration of 'printf'
prog.c:17:9: warning: incompatible implicit declaration of built-in function 'printf'
         printf("Roots of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
         ^~~~~~
prog.c:17:9: note: include '<stdio.h>' or provide a declaration of 'printf'
prog.c:23:9: warning: incompatible implicit declaration of built-in function 'printf'
         printf("Roots of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
         ^~~~~~
prog.c:23:9: note: include '<stdio.h>' or provide a declaration of 'printf'
0 like 0 dislike
Hidden content!
***** * * *** * **
int main()
{
* * ** * * ** **** a,b,c,D;
*** ** * ** * *** * ** x1,x2,r,i;
* * ***** **** ** * * * * * * * ** ******** ** ** ** *** *
* * * ** ** ****** *** * ** * * * *
* * * ** **** **** ** ** **
** ** * * ** * *** ** *** *
**** * * * * * ***
* * * * ***** ** ** *
*** * * * ***** * *** *** **** * * * ** * ** ** * of %.2fx^2 + %.2fx + %.2f = 0 are real and same\n",a,b,c);
* * * ** ** * * *** **** * * ** * * ** * * = x2 = %.2f",x1);
***** * * ** *
* * * *** ** ***** ***** if(D>0)
* * * ***** *** * ** * **
* * * **** ** * **** * * *** * ** * **** * * * *** *** of %.2fx^2 + %.2fx + %.2f = 0 are complex and * * * ******
** * * * * * * ** * **** * ** ** * **** * *** ***** * = %.2f\n",x1);
**** ** * * * **** ** * * ****** ** * *** * * = %.2f",x2);
* ** * ****** * *
** *** * *** ***** ** if(D<0)
* **** * * * * * *
* * *** ****** * * ********** ** ** * * * * * **** * * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\n",a,b,c);
* **** * * ***** * * * ** * ** * ** * * * -b/(2*a);
**** ** *** * *** ** * * ** * * *** * * ** * * **
**** * ** * *** *** **** ** ** ** ** ** * * * = %.2f+%.2fi\n",r,i);
* * * * * ** * ** * ** *** * * ** * * * * *** = %.2f-%.2fi",r,i);
** ***** * * * * ***
}
answered by (-329 points)
0 0
prog.c: In function 'main':
prog.c:8:12: warning: implicit declaration of function 'sqrt' [-Wimplicit-function-declaration]
     x1=(-b+sqrt(D))/(2*a);
            ^~~~
prog.c:8:12: warning: incompatible implicit declaration of built-in function 'sqrt'
prog.c:8:12: note: include '<math.h>' or provide a declaration of 'sqrt'
0 like 0 dislike
Hidden content!
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main()
{
** ** * **** * *** * **** a,b,c,d,x1,x2;
* * * ** **** ** * ** ** * ** **** *** * * * ** * * ******
* * ***** ** * * * ** ** * *
*** *** **** * *** ** ** **
* * ****** ** * ** * ** * ***
** * * * * * * *** ** ***
* *** ** ****** **** ** **
* *** * * ** * * * *** *** * ******* * * * of %.2fx^2 + %.2fx + %.2f = 0 are real and * ** ** ** * *
** * * * ** ** * * * **** * ********* ** * * * * ** = %.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 ** * * **** ** ** *
* ** ** **** * * *** *** ****** * * *** * **** * ** ******** = * * *** * *** ** **
****** **** ** * * * * **** *** ** **** *** ** * * * = **** ** * **** **
* *** ** * ** ** **
* ******** ** * * * * * * * 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 <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
***** * ** * **** ** * ** * * a,b,c,d,x1,x2;
** **** ** * ******* *** **** * ******* ** * * ** **** * *
*** *** **** ** ***
* * * * ** * * * = (-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 (-108 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 * * * * ** **
#include * ** * * *

int main()

{
******* * * * * *** ** * *** ** ***** *
*** ***** *** *** * ** *** * %f *** * * *** * **** *** *

**** ** * * * *** * * **
*** **** * ** * *** ** * ** + sqrt(D))/(2*a);
** ** * ** *** ** ** *** ** * ** - *
* ** * * * * ** * * *** * ** *
* *** * ** ** ***** ** * * *

* **** ** * ** (D==0)
** ** * ** * ** * *** ***
* ** * *** ** *** ****** * **** ****** *** * *** * **** * * of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = * * ** ***
* * ** * * ***** * **
* * ** * * * ** * ** * ** * ** * if (D>0)
* * *** * *** *** *
******* *** ** **** ** * *** ** * * *** * *** *** *** ** of %.2fx^2 + %.2fx + %.2f = 0 are real and different\nx1 = %.2f\nx2 = ***** ******** *
*********** * ** *** **
* * * * ** * * * * *
* * ** * * * ** **
* **** ** ** ** * ** * * * ** * * *** *** ** of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\nx1 = %.2f+%.2fi\nx2 = * * ** * * * *****
* ** **** *** * * ** * *

* ** **** * * * * * * * 0;

}
answered by (-249 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 ***** * *
#include ** ***** ***
int main(void)
{
float a,b,c, D, x1, x2,i;
***** *** * * * **** * ** * * %f ** * * &a, &b, &c);
* **** ** *** * *** *** * * **
* *** * *** ** *** * * * (D>0)
* ** * * * **** ***
* ** * ** * *** * * * *** *** * * * * ** * ** * *
**** * ** *** * * ******** * * ** *** ** * * * * ** * ***** **

** ** * ** * ** *** ****** * ** * * *** * ** * * ** * * * **** 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 = * **** * **
** *** ** * * * *
*** * ** * * * ***
** * * * ** *****
**** ****** * *** ** *   x1=x2 = -b/(2*a);
* ******* *** * ** * * ** ** * ** * *** * * *
*** * ** * * ** * * **** **** ** **** **** ** * * * * ***** of %.2fx^2 + %.2fx + %.2f = 0 are complex and ** ** = ** ** * = * *** * *** x2,i);
** * ** * * *********



* *** * * * *** * 0;
}
answered by (-304 points)
edited by
0 0
prog.c: In function 'main':
prog.c:10:16: warning: implicit declaration of function 'sqrt' [-Wimplicit-function-declaration]
         x1=(-b+sqrt(D))/(2*a);
                ^~~~
prog.c:10:16: warning: incompatible implicit declaration of built-in function 'sqrt'
prog.c:10:16: note: include '<math.h>' or provide a declaration of 'sqrt'
0 0
Case 0: Correct output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output
0 0
prog.c: In function 'main':
prog.c:21:5: error: expected ';' before '{' token
     {
     ^
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output
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()
{
* ** ** ** **** * * ** a, b, c, * * *** x1,x2, realPart, ** *


*** * ** * * * * **** ****** * %lf * * ** * * &b, &c);


*** * * * * * ******* * **** * = b*b-4*a*c;

* * * * *** * * condition for real and different roots


** * * ***** **** * * * ** * for real and equal roots
* ******* *** * * ** * (determinant == 0)
** * *** * ** * *** * ****
* * ** ** ***** *** *** * * * * * * * * * = x2 = -b/(2*a);
* * **** ** *** **** * * *** ** * ***** ** * ** * * of %.2fx^2 + %.2fx + %.2f = 0 are real and * * *** a,b,c);
* * ** ** * * ***** ** *** * * *** *** * * = x2 = * ** * x1);
** ** ** ** * **

* *** ** * ** ******* * ** * * if (determinant > 0)
* * * * ** ** **** *
*** * ******** * * ** ** sqrt() function returns square root
** * * * ********* * * ** * * *** ** ** * ** = *** * * * ** ****
* * *** * *** * ** ** * ** * **** **** **** *** = * ** * ***

** * ** * * * *** * *** * * * *** *** ** ** ** *** * ** * ** of %.2fx^2 + %.2fx + %.2f = 0 are real and * * ********
** ** * * **** * * * * * * * = *** ** * x1);
* ** * ******* * ** * * * *** * *** **** = * * ** ** x2);
****** *** * * * * * if roots are not real
***** * * * * * * * ** *
** * * * * * * ** * **
* ** * * * * * * * ****** ** * * * * * = -b/(2*a);
** * ** ********* * * ** * * * * **** * * ** = * * **** ** *
* * * **** *** ** * ** * *** ** *** * * * ** *** of %.2fx^2 + %.2fx + %.2f = 0 are complex and * *** *** a,b,c);
* *** **** * * ** * *** * * * * **** ******* ** * **** = * * * * realPart, ***** *
*** ** ***** * * *** ***** * * * *** ** * * ** ** * ****** *** = * *** * * * realPart, *
** * *** * * * *** *

**** * * ** *** **** * * 0;
}
answered by (-167 points)
0 0
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
Welcome to Peer-Interaction Programming Learning System (PIPLS) LTLab, National DongHwa University
English 中文 Tiếng Việt
IP:172.69.6.252
©2016-2024

No related questions found

12,783 questions
183,443 answers
172,219 comments
4,824 users