0 like 1 dislike
12.3k 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 | 12.3k 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 * ****
#include *** * ** * **

int main()
{
** **** * * a, b, c, determinant, 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 **** > 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: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 like 0 dislike
Hidden content!
#include * * ** * ** *
#include * ** * **

int main()
{
* ** ****** * ** * ** * * a, b, c, determinant, x1,x2, realPart, ** ** *


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


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

* * ** ** *** ** * * condition for real and different roots
** * ** *** *** * * *** (determinant > 0)
* * **** * * * **
* * * ** * * * *** ** sqrt() function returns square root
* * **** *** * ** *** ** ** * * * * = *** * * ** *
* * * ** * ** * * *** ****** * = * * *** *** **** *

* * ****** * * ****** *** **** ** * **** * ** * ****** *** * of %.2fx^2 + %.2fx + %.2f = 0 are real and * ** *
* ***** * ** ** * ** * * ** **** ** * *** * * *** ** = * * x1);
***** *** * * *** * *** ** * * * * *** * * ***** * = ** ** x2);
*** * * * * * * **

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

* ** ** * * ** * 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: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 like 0 dislike
Hidden content!
* ** **** * * **
** *** *** * * ***
int main(void)
{
* * *** * ** * * * a,b,c,d;
**** * *** * * **** * * * %f * **** * * ** *** * * ***
** * *** * *** * ** ** * ** *
* ** * * *** ***** * **** ***
* * * * * ** * **** * * ** * * *** * ** ** ** *** ***** ***** of %.2fx^2 + %.2fx + %.2f = 0 are real and *** *** = %.2f\nx2 = ** * ****** * + ** **** * - **** ** **
* * **** * ** **** **
** ***** ** ** * * ***** (d==0){
** * **** * * **** ** ** ** * * * ** *** ** * ******** of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = * ** * ***** + **** *
* *** * * * * ****
*** **** * ** ****** **** ** (d<0) {
** ** *** * * * * * * * * * * * * * ** *** ** of %.2fx^2 + %.2fx + %.2f = 0 are complex and * ** = ** * * = * ** * * *** * * * ** * ** * * ** * ***
**** *** * *** * * *****
}
answered by (-204 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!
*** * *** * * *
* * *** * ***** ****
int main(void)
{
* * **** ** ***** * ***** * a,b,c,d;
** * *** * **** ** ***** * ** ** ***** %f *** *** *** ***** *** **
*** * * * **** * * ** * *
* * ** * ** *** * ** * (d>0){
* *** * ** ** ***** * * ***** ** *** * * ** * * of %.2fx^2 + %.2fx + %.2f = 0 are real and *** * * = %.2f\nx2 = * * ** * * + * * * ** * - **** *****
*** ***** * ** * *
** * **** * ** * ** * * * (d==0){
* * * ** ** ** ** *** * *** * ** *** * * * ** ** of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = * *** * *** + **** * *
*** ** * * * * *** * *** * *
****** ** ****** * *** * {
* ** ** ****** * * ** * ***** *** * * ** * * * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and * * *** = ** * * = ** *** * * **** ***** *** * ** *
* * * * **** * *** * **** *
}
answered by (-204 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<math.h>
int main()
{
*** * ** * * **** * *** a,b,c,d,x1,x2,x3,x4;
* * ** * * * ******* * * *** * * %f * * * * ** **
** * ****** * * *** *
* **** ** ******* ** * **** *****
* * * **** **** * ***** * **** * **
* * ** * ** ******* ** ***** ***
* ** ** * * * ** * ** ** ** * ** ***** *
* * ** * *** ** *** * ****** * ** * *** * * * *
** ** * * * *** ***
** * ******** ** * * * * *** ** ** * ****** * *** *** * of %.2fx^2 + %.2fx + %.2f = 0 are real and * ***** *** *** **** * *** * **
* ***** ** ** * * *
* ** ** * **** * * * * * *
***** * ** ** * ** * *
* ** ** **** ** * ***** * * * * * * * ****** * * of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = %.2f",a,b,c,x1);
* ** * * * * * ** ** ***
*** *** ***** * * * ******* ** ** ** *
** ** * *** * **** * *
*** * * ** *** * * * ** * * ** * * * * ** of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\nx1 = %.2f+%.2fi\nx2 = * ** * ** * * ***** **
* * * * ** ** *** * ***
* * * * * ** *** * 0;
}
answered by (-255 points)
0 0
prog.c: In function 'main':
prog.c:5:5: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
     scanf("%f %f %f",&a,&b,&c);
     ^~~~~
prog.c:5:5: warning: incompatible implicit declaration of built-in function 'scanf'
prog.c:5:5: note: include '<stdio.h>' or provide a declaration of 'scanf'
prog.c:13:9: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
         printf("Roots of %.2fx^2 + %.2fx + %.2f = 0 are real and different\nx1=%.2f\nx2=%.2f\n",a,b,c,x1,x2);
         ^~~~~~
prog.c:13:9: warning: incompatible implicit declaration of built-in function 'printf'
prog.c:13:9: 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 real and same\nx1 = x2 = %.2f",a,b,c,x1);
         ^~~~~~
prog.c:17:9: note: include '<stdio.h>' or provide a declaration of 'printf'
prog.c:21:9: warning: incompatible implicit declaration of built-in function 'printf'
         printf("Roots of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\nx1 = %.2f+%.2fi\nx2 = %.2f-%.2fi",a,b,c,x3,x4,x3,x4);
         ^~~~~~
prog.c:21:9: note: include '<stdio.h>' or provide a declaration of 'printf'
0 like 0 dislike
Hidden content!
#include<stdio.h>
#include<math.h>
int main()
{
** * * ** ** * ** *** a,b,c,d,x1,x2,x3,x4;
** ** * * * * * ** ***** * * ***** %f * * * * * * **** * ** ****
*** * ****** ** * ***** ** ** ***** ** *
* ** * * ** *** **** ** * * ****
* * ** ** *** *** ** ** ** * *
*** ** ** * ***** **** *** * ** ***
*** ** * * ** ** ** ** **** * * ***** *
* * ***** * * **** ** **** ** * ** * * *
***** * * ** ** ** *** * **
** * ** * ** * *** ******* ** ********* * ** ** of %.2fx^2 + %.2fx + %.2f = 0 are real and * ** ** *** ***** * ** ** **
* * ****** * * *****
*** * *** *** * * *** ** * ** *** **
** *** * * ** ** *
* ** * * **** ** ** * ** * ** * ** *** * * *** * *** of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = %.2f",a,b,c,x1);
* * **** ** *** * * *
***** * ****** * ** * * ******** * * *** *
* * * * ** ******
* * * ** **** ** ** * *** * **** *** * * * ** ***** * * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\nx1 = %.2f + %.2fi\nx2 = %.2f - * ***** * ***
** * * *** ** * * * *** *
** ** ** * ** * * * * 0;
}
answered by (-255 points)
0 0
Case 0: Correct output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 like 0 dislike
Hidden content!
#include<stdio.h>
***** ** * ***
int main()
{
* * * * * ** ** a,b,c,d,x1,x2,x3,x4;
* ** ***** ** * ** * * * ** * %f * **** * ** * *
** * ********* ***** ** ********* *
** * **** * *** *** * * **** *
* * ***** * * * *** * * *** ** *
**** ** * ****** *
* * ******** *** *** * ** ** ** *
*** * *** ** ** ** * *** * * *** ***
**** * * ********** *
* * * * ** ** *** ** * * **** * * ** * ** * *** ** of %.2f x^2 + %.2f x + %.2f = 0 are real and ** * * * * ***** * ** * *
**** ** * * ** * * *
** ** **** *** ** * * *** * *** **** ** ** ***
* *** ** ****** * * *** ***
** * * ** ** ** **** * ** *** * * * * * * * ***** * ** of %.2f x^2 + %.2f x + %.2f = 0 are real and same\nx1 = x2 = %.2f",a,b,c,x1);
* * * ** * * ** *
*** ** * * *** * ** * * * ** * * * ** *
* * ** * * ** * * * **
* * * **** * * ** * * * * ** ** * ** * * * of %.2f x^2 + %.2f x + %.2f = 0 are complex and different\nx1 = %.2f + %.2fi\nx2 = %.2f - **** *** * * **
*** * ** ** * ***
* * **** * ** * * * * * 0;
}
answered by (-255 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!
#include<stdio.h>
#include<math.h>
int main()
{
* * **** ** * * ****** a,b,c,d,x1,x2,x3,x4;
* ** * * * *** **** * ** * ** ** %f * ** * ** * * * * ** * *** **
** ** * *** * * * * ** ****
**** * *** * * * *** ** **** *** * **
** *** ** ** * * ***** *** * *** ***
*** * **** * * * **** ** * * *
* ** * * * * * * *** * **
* **** ** * ** **** * * *** * **
** * *** ****
* ** **************** ** ** *** ******** ** ** *** * of %.2f x^2 + %.2f x + %.2f = 0 are real and * **** * **** ****** **
* ** * ** *
* * * ***** * * * *** * * * **
* * ** *** ***** * **
* *** ***** * * * * ** **** * ** * * * ******** * of %.2f x^2 + %.2f x + %.2f = 0 are real and same\nx1 = x2 = %.2f",a,b,c,x1);
* * **** *
* * * * *** ** * ** ** * ** ** * *** *** *** *** *
*** * * * **** ***
* ***** ** * * * * *** ** * ** * ** **** * * * ** * * * of %.2f x^2 + %.2f x + %.2f = 0 are complex and different\nx1 = %.2f + %.2fi\nx2 = %.2f - ***** * * * ** *
** *** * * * * *
*** * * * * ** ****** * * * ** ** *
** ******** * * ******** ** *** 0;
}
answered by (-255 points)
0 0
prog.c: In function 'main':
prog.c:24:5: warning: implicit declaration of function 'system' [-Wimplicit-function-declaration]
     system("pause");
     ^~~~~~
0 like 0 dislike
Hidden content!
#include<stdio.h>
#include<math.h>
int main()
{
* ********* * * a,b,c,d,x1,x2,x3,x4;
*** *** ** **** * * * ** ***** * %f * * * * *** * * * *** ***
* *** * * * * ** ** * ** *
** ***** * ****** **** * ** ****
***** * *** ** * ** * ** * * * *** **
*** ** * ***** * *** ** *
** * *** * *** ***** * * * * ***
*** * * * *** ** * ** * **** ** * ****** * **
** * **** * * * * ** *
** * * * ** * ** ** **** ***** * *** **** ** * * * * of %.2f x^2+%.2f x+%.2f=0 are real and different\n x1=%.2f\n * ** *** *** *
*** ** *** * *** * ****
** * ***** * * * ** *** * * * ** *
* * * ** * *
* *** ** *** ** ***** **** *** * * ** * * * ** ****** ** of %.2f x^2+%.2f x+%.2f=0 are real and same\n ****** ** * * *
***** * * **** * ***
* *** * ** * * *** * *** * ** ***
**** ** * ** ** ***
** ** ********* * ***** ** ** * ** ** ** ** * * of %.2f x^2+%.2f x+%.2f=0 are complex and different\n x1=%.2f+%.2f i\n x2=%.2f-%.2f ** * * * * ***
*** ***** *** ** * *
* * ** * * * * * * * 0;
}
answered by (-255 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!
#include<stdio.h>
#include<math.h>
int main()
{
***** *** *** **** * a,b,c,d,x1,x2,x3,x4;
**** *** ** ** * ** * *** * %f ******* **** ** **
* * * * * * * * *** **
** * **** * ** ***** ** * **** *
*** * ** *** ** * * * ***
* *** * *** * * * * * * ** ******
* ** * ** *** * * ** ***** * * *
** * * ** **** ** ** ** *** ** ** *** * *
* ** * **** * *** * *** **
* ** * * ** * * * ** *** ** * *** ** ****** * * * * of %.2f x^2+%.2f x+%.2f=0 are real and different\n x1=%.2f\n ** * ** * *
******** *** * * **
** * * * ** * * * *** *** * * * * * ****
** **** ** ****** ** *
* ** * *** ** * * ** * * * * ** ** * * * *** *** *** * * *** of %.2f x^2+%.2f x+%.2f=0 are real and same\n ** * ** ***** ***
* *** ** ** * * *
* * * ** * * * ***** *** * ** *** ** * * *
** ** * **** * ****** **
* * *** ** * * * **** * * * * ** * * * ** of %.2f x^2+%.2f x+%.2f=0 are complex and different\n x1=%.2f+%.2f i\n x2=%.2f-%.2f * ** * ** ****
* * * * * ** * *** ** *
** *** ** * * ** ** * * * 0;
}
answered by (-255 points)
0 0
prog.c: In function 'main':
prog.c:18:16: warning: too many arguments for format [-Wformat-extra-args]
         printf("Roots of %.2f x^2+%.2f x+%.2f=0 are real and same\n x1=x2=%.2f",a,b,c,x1,x2);
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Welcome to Peer-Interaction Programming Learning System (PIPLS) LTLab, National DongHwa University
English 中文 Tiếng Việt
IP:108.162.241.33
©2016-2025

No related questions found

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