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:172.70.194.138
©2016-2025

No related questions found

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