0 like 1 dislike
9.5k 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 | 9.5k 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
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()
{
* * **** ** ** * *** **** *** n, i;

** * * * ** ** * * *** * * ** * * &n);

** *** *** * *** = 1; i <= n; ++i)
* ** ** ** *** * * **
* ** ** ***** * ** * ** ***** ** *** * * * * % i == 0)
***** *** * * * * ** * * ****** * ** ** *** * * * * * * ** *** ", i);
* * *** * ** * ****

*** ** * **** * * **** 0;
}
answered by (-284 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()
{
* ** *** *** * *** ** *** * * * *******
**** **** ** *** **** **** * *** * *** ** * * ** * * * ** ***
** ***** * * * * * * = ***** * *
**** * * ***** * **** *** * * *
*** ** *** * *** * *
*** * * **** *** ** * *****
* * * ******** ***** * = -b /(2*a);
** ******* ** * *** *** **** * * **
** * ****** ** = (-b)/(2*a);
* ** ** **** ** * * ** * *** of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\nx1 = %.2f+%.2fi\nx2 = *** ** **** * ** **
*** * * *** * * *
**** * * * ** ** * * * if(D==0)
** * * * ** ** ** **
** ***** * * * *** = (-b + **** * **
* ** *** * * * *** * = (-b - * ** *
****** ** * * ** * **** *** * * ** * * of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = ***** * *
** ** ** **** **** *
* ** ******* ** *** * ** * if(D>0)
** *** ****** * ** * *
** * ** **** * * * * *** * * * = -b/(2*a);
***** ** ** * * * * = (-b + ** * * ***
* * ** * * *** * * * ** = (-b - ** ** **
** *** * * ******** ** ** * ** *** of %.2fx^2 + %.2fx + %.2f = 0 are real and different\nx1 = %.2f\nx2 = ** ** *** **
** * ****** * **** *
** * * * * * * * * *** * * * *** 0;
}
answered by (-323 points)
edited by
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: Wrong output
Case 2: Correct output
Case 3: Wrong 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;
** *** ** * * ** * ** * ****** * * * ***** ** *
* ****** * ** * * *
*** * * * *** * * ** *****
** ** * ** * * * * ** * * **
** * ***** * ***** ******* * ** ******** *** * **** of %.2fx^2 + %.2fx + %.2f = 0 are real and different\nx1 = %.2f\nx2 = **** * *** * * + ** * ** ** ** - * * **** ** *
* * *** * ** * ** ***
* * * * * **** **
* * * * ** * *** * * if (b*b-4*a*c==0)
* ** **** ** * *
** * **** * * * ** * * ** * ** ** ** ********* *** ** * * of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = ** * * ** + ***** * *** **
* ** ** *** * ****
* **** *** *
* * * ***** * * **** ****** *
** * ***** ****
* * * **** * * ** ** ** ** ****** * ***** ** *** * *** of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\nx1 = %.2f+%.2fi\nx2 = * * ** ********* * * * * * * * * ** * * *
* ** * * * * * *** *
***** ** ** ** *** * ** * 0;
}
answered by (-127 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()
{
* * ** ** * ** a,b,c;
* ** * *** * **** * * * * * *** * * * ** * * *
* * * ** * * * ** **** *
** ** *** * * * * ** * * ** ******* ** **
* *** * * *** *
* ** ** ** * ** *** *** * * ** * * * ***** * * of %.2fx^2 + %.2fx + %.2f = 0 are real and different\nx1 = %.2f\nx2 = *** * * ** + * ** *** - * * *** ** * *
** * * * * * * **
* * * ** ** ** * ** * ***
** * ** ** *** ********** if (b*b-4*a*c==0)
* * **** * * * ** **
* * * * * ** * * * ** ** * ** * * * of %.2fx^2 + %.2fx + %.2f = 0 are real and same\nx1 = x2 = ** *** ** + * *******
* ** ** *** **** *** *
* * *** * * ** * * **
* * **** * * **** * * *
** * * * ** *
* * * ** * * ** ** * * **** ** * *** *** * ** * * * of %.2fx^2 + %.2fx + %.2f = 0 are complex and different\nx1 = %.2f+%.2fi\nx2= * * ** *** **** ** *** * *** * * *** *** * ** *
* * ** ** ** **** *
* *********** * * * *** 0;
}
answered by (-127 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,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 (-214 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 a, b, c, D, spD, x1, x2;
*** *** * *** **** * * *** *** * * *** *** ** ** ***** * aX^2 + bX + c = 0\n以a b c表示\n");
    while(scanf("%d %d %d", &a, &b ,&c)==3){
** **** * ** * * * * *** * **** * *** * * - (4*a*c);
*** * * ** ***** * * * ** * * * ** ***** * *** ** *** * *
*** * * ** * ** *** **** *** * * ** * * * * * *** *
** * * ** * * * * **** * *** ** *** * ** * ****** * ******* **** * *** (-b+spD)/(2*a);
* * * * *** *** * ** ***** * * * * *** ** *** * ** ** * * * (-b-spD)/(2*a);
* * *** * ** * * * * * * * *** ** ** * * ** * ** ** * ** ** **** (x1==x2){
* * * * * * * * ** ** ** ** * *** * * * * * * **** ** *** * ** ***** ** * * **** * *** * ** ** * **** * * X=%d\n", x1);
*** * * ******* * * ** * ** **** * * ** * **** *** *** *** * * **
* ** * *** * ****** **** ***** ** ******* * * ** * ** * * * *** ** *** {
* * * * * * ** * * ***** * * *** * **** ** ** ** ** * ** **** ** ****** ** ** *** **** ** * * ** * ** *** ** X=%d或%d\n", x1, x2);
* **** ** ***** * ********* * * * * * ** ********** * * ** * * * **
        }
* ** *** * * *** * * ** ** * *** **** * * if(D==0){
* ** *** **** * * ***** **** * * * ** * * ****** ** * * ** * * ** *** (-b)/(2*a);
* * * ** * * ** **** * ** * *** * **** **** * * * ** **
* * ** ** * ** * ** ******* * * *** * * ***** ** * *** * ** * * * ** * * * * ** *************** * *** ** X=0");
* * ** * * * * *** * ** ** ** ***** * * ** * * *** * * **
* ** * ** * ****** * * *** * ** ** * **** * ** *** ** **
**** * ** ** ** * ** ** *** ***** * ** ** ** * **** * **** * ** ** * * * **** *** * * * *** * * X=%d\n", x1);
*** **** * * * * * ** *** *** **** **** ** * * ** ** * * ***
        }
* * ** ** * * * *** ****** * ** ** ***
* ** * ** ***** * ** ** *** * ** * *** ** * ** * * ** * * **** ***** * * * * ** * * * * *
* * ** * ** ** * * *** ****** ** **** **
    }
* ** *** ** * * *** *** * * * * * ** * ** * *** **
    system("PAUSE");
    return 0;
}
answered by (-32 points)
0 0
prog.c:2:12: error: expected declaration specifiers or '...' before string constant
     printf("\xe8\xab\x8b\xe8\xbc\xb8\xe5\x85\xa5\xe4\xb8\x80\xe5\x85\x83\xe4\xba\x8c\xe6\xac\xa1\xe6\x96\xb9\xe7\xa8\x8b\xe5\xbc\x8f\xe7\x9a\x84\xe4\xb8\x89\xe5\x80\x8b\xe4\xbf\x82\xe6\x95\xb8\xef\xbc\x8c\xe5\xa6\x82 aX^2 + bX + c = 0\n\xe4\xbb\xa5a b c\xe8\xa1\xa8\xe7\xa4\xba\n");
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:3:5: error: expected identifier or '(' before 'while'
     while(scanf("%d %d %d", &a, &b ,&c)==3){
     ^~~~~
prog.c:29:12: error: expected declaration specifiers or '...' before string constant
     printf("\xe8\xab\x8b\xe8\xbc\xb8\xe5\x85\xa5\xe6\xad\xa3\xe7\xa2\xba\xe7\x9a\x84\xe4\xb8\x89\xe9\xa0\x85\xe4\xbf\x82\xe6\x95\xb8");
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
prog.c:30:12: error: expected declaration specifiers or '...' before string constant
     system("PAUSE");
            ^~~~~~~
prog.c:31:5: error: expected identifier or '(' before 'return'
     return 0;
     ^~~~~~
prog.c:32:1: error: expected identifier or '(' before '}' token
 }
 ^
0 like 0 dislike
Hidden content!
#include <math.h>
#include <stdio.h>
#include <stdlib.h>

int main ()
{
****** * ***** *** * a,b,c,D;
*** * * * ** ****** * x1,x2;
** ** ** ** * ** ** ** **** *** %d * * * **** *** ****

*** ** * ** * ** **
**** **** * *** * ** * ***
** * ** * * * * *** * * * * **

*** ** ** * * **** A,B,C;
**** *** * *** ** *** * * *

** * * * * * * ** * * ***
* * * * * * *** * * **** * * ** * ** * *** **** * **** ** 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);}

** * * ** * * * ** ** if(D<0)
* ** ****** *** * ** * * ***** * * ** ** * * ***** ** * * of %.2fx^2 + %.2fx + %.2f = 0  are complex and ** *** * * ** ** *
* **** * * **** * * **** * * * **** ** **** * * ** bb,d,dd;
* ** *** * * * * * *** *** ***** * ***** ** ** *
** ** * * ****** ** ** ** * *** ** ** ** ** ** *
* * **** ** ** * * *** ******* *** *** * * * ** * * = ** **** * ** ******
* * **** * * * * *** * *** * * ** **** ****** * * * ** * * * = * * * * ***** ** **

**** * * * * * ** * * ** * 0;
}
answered by (-16 points)
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: Wrong output
Case 2: Wrong output
Case 3: Wrong 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 %.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
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 %.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
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:172.69.59.173
©2016-2025

No related questions found

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