0 like 1 dislike
12.2k 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 | 12.2k 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:172.70.131.12
©2016-2025

No related questions found

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