0 like 1 dislike
9.2k 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 | 9.2k 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!
* **** ********
# * * * * * ***
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 complex and ** *** * * ** *
** * * ******* *** ****** ** * * * * ** ** * * * **** ** = -%.2f+%.2fi\n", realPart,imaginaryPart);
** * * ** * * * * * * * *** ** * * ***** * * * * = -%.2f+%.2fi", * **** ********
* * ** ** * ** * * * **
* * ** ** * * *** if(D == 0)
* * * ** * ** ** **

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

}
answered by (-281 points)
0 0
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 0
/tmp/ccgUqSsU.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x14c): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 0
-----------Re-judge-----------
Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output
0 like 0 dislike
Hidden content!
#include * ** ** * * *
#include <math.h>
int main()
{
* * * ** * * ** * * a,b,c,x,y,d;
**** ***** ** ** * ** * * %f * ** * * * ** * ** *** *
** ** ** *** ** ** * ** ****
** *** ** ** * * * *** * * **
* * * ***** ** ***** * ***
**** *** * * ** ** * (d>0){
******* ***** *** ** * *** * ** * * ** of %.2fx^2 + %.2fx + %.2f = 0 are real and ** ******* * **
** * * * ** *** ** * ****** *** = %.2f\nx2 = %.2f",x,y);
** ** *** * * * *
** ** *** *** *** ** if (d==0){
* ** ** ** ** * ** **** * *** * * ** of %.2fx^2 + %.2fx + %.2f = 0 are real and * * *** *
** ***** * ** * * * ** * * * * ***** = x2 = %.2f",x);
** **** ***
* * * *** * * * * * *
* *** * * * * * ** * *
***** ** ***** * *** * *** * ** * of %.2fx^2 + %.2fx + %.2f = 0 are complex and **** ** *
* *** ** ** *** * * ** ** ** ** * *
** **** * ***** *** ** * ** * = ********* ** ***
* ** ** * ** * *** ** * * = *** * * *
* ** *** ** ******* *** **

* * * * * * ****** * 0;
}
answered by (54 points)
0 0
/tmp/cc8k7Xv8.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x21f): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 like 0 dislike
Hidden content!
#include * * **
* * * *** ** * **

int main()
{
** ** * *** * ** ***** a, b, c, D, * * * * * realPart, * * *

* * * **** * * *** ** ** *** %lf * *** **** * **** * * *

** * ** *** * **** *** * = *****

** * * ** * * *** ** (D > 0)
** ** ** * ****** ** *
* ** * ** ** ** * * * ** *** ** ** *** ** ** * * = * ** * * *
* ****** *** * *** *** * * * * * ***** ** * ** = *** * ** *

** * ***** **** * ** * ** * **** * * *** ** * * * *** of %.2lfx^2 + %.2lfx + %.2lf = 0 are real and ** ** = %.2lf\nx2 = ** *** ***** ** b, c, root1, root2);

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

* * *** * * * * *** ** * * if (D == 0)
* * * * *** ****
** **** *** * * * **** * ***** * ** * * * ** = root2 = -b/(2*a);

* * ** * * ** * ** * **** * *** * * * ****** *** *** of %.2lfx^2 + %.2lfx + %.2lf = 0 are real and same\nx1 = x2 = ** * a, b, c, root1);
* * * ** * **** *

* ** * ** ** ** ** **
*** ** ** * * * * * * * **
***** **** * * ** * * * * * * ***** * **** *** * ** * * = -b/(2*a);
**** ** * * * * * *** * **** * **** * ** * *** * = * * **

* ***** ** * * * * ** ** *** *** ** * ** * ** * * * of %.2lfx^2 + %.2lfx + %.2lf = 0 are complex and ******* = * * ** * = ** ***** ** a, b, c, realPart, **** * * realPart, * *
* * **** * * *** * * * *

******** ***** **** **** * ***** *** * * ** **
* *** * ** * ** * *** 0;
}
answered by (5.2k points)
0 0
/tmp/ccibyL4w.o: In function `main':
prog.c:(.text+0x89): undefined reference to `sqrt'
prog.c:(.text+0xd4): undefined reference to `sqrt'
prog.c:(.text+0x1fc): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 0
/tmp/ccfjcMIR.o: In function `main':
prog.c:(.text+0x89): undefined reference to `sqrt'
prog.c:(.text+0xd4): undefined reference to `sqrt'
prog.c:(.text+0x1fc): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 0
-----------Re-judge-----------
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
1 like 0 dislike
Hidden content!
#include <stdio.h>
#include <math.h>

int main()

{
** * *** ** **** * * * * ** ******

* * *** * *** ** ***** * ** %2f * * * * *** **** **** *** *
**** ** ** * ** ** * = (b*b-4*a*c);
* *** *** * * ** = (-b + sqrt(D))/(2*a);
****** ****** * ***** = (-b - sqrt(D))/(2*a);
**** * * ** *** *** * * * ** = -b/(2*a);
* * ** ** ** *** *** * * =sqrt(-D)/(2*a);

* *** * * ***** **** * * * * (D==0)
* *********** ** ***** *
* ** * ** ****** * * *** ** ***** *** ** * * ****** * ** of %.2fx^2 + %.2fx + %.2f = 0 are real and *** * **
* * * *** * * **** * * ** ** * *** ** * * ** = x2 = %.2f",x);
* * ******** ** * *
***** ***** * * * ** ** *** if (D>0)
****** * ** ** * **** * *
** * * *** * ***** ** * * * ** * ** * ** * *** * * of %.2fx^2 + %.2fx + %.2f = 0 are real and *** ***** ** * *
** * ***** *** ** **** * * * ** * ** ***** * = %.2f\n",x);
** **** ** * ** * * * * * *** * **** ****** ***** * * ** = %.2f",xx);
*** *** * * * * * * *****
** * * ******* * **
*** * * * ***** ** * ** *
**** * **** * ** *** * * **** ** * * * ** *** *** * of %.2fx^2 + %.2fx + %.2f = 0 are complex and ** ** * *** *
** * *** ** **** *** **** ** * * * * *** **** * * *** * *** * = ** * ** ** **** ** *** *
** ** * ***** * * *** *** *** ** ** * * *** * * = * * * ** **** ** *
*** * ** ** * ** *

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

}
answered by (-249 points)
0 0
/tmp/ccwpNp77.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x13e): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 0
/tmp/ccWys99e.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x13e): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
0 0
-----------Re-judge-----------
Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output
0 0
-----------Re-judge-----------
Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output
1 like 0 dislike
Hidden content!
* * ** * * *
*** **** ** * *
int main(){
** * * ** ** *** ** * * a,b,c;
** ** ****** * * ** *** D;
* * ** ** ** * ** * ** * %lf * *** ** ** ** * **** ** * * ** *
* * * *** * * ******* - 4*a*c ;

* * * *** ****** * ** * *** * of %.2fx^2 + %.2fx + %.2f = 0 * * ***

** ** * **** * ** * ** ** * * **
* * * *** ** **** ***** ****** ** ***** ** * * * *** * complex and *** ** * **
* **** ** ** * * * ** ** * * ****** * * **** ** = * * * * ** * * (-b) / (2*a) ), sqrt(-D) / (2*a) );
****** * ** * *** * * ** * * * * ** * * ** * = * * * * * * *** (-b) / (2*a) ), sqrt(-D) / (2*a) );
* * **** *** * ******
*** **** ** * ** ** * *** if(D==0){
* *** ***** * ** *** **** * * ** * ** **** **** ** * * * real and same\n");
**** **** * * * *** * ** * * * ** *** ** ** * = x2 = %.2f",( (-b) / (2*a) ) );
* * * * * * **** *
* ** ** *** * * * ** * ** ** **
* ** * * * ** ** **** *** * ** ** ** * * * ** real and * * **** * *
* * * * **** ** ** *** * ** * ******* ** * ** * * * ** * ** = %.2f\n",( ((-b) + sqrt(D)) / (2*a) ) );
* ** * * * *** * * * * ******* * *** * * * * ** = %.2f", ( ((-b) - sqrt(D)) / (2*a) ) );
* * ** * ** * ***** ***

* **** * ** * * *** ** * ** 0;
}
answered by (-116 points)
0 0
/tmp/ccpv8G38.o: In function `main':
prog.c:(.text+0x51): undefined reference to `pow'
prog.c:(.text+0xdd): undefined reference to `sqrt'
prog.c:(.text+0x13f): undefined reference to `sqrt'
prog.c:(.text+0x213): undefined reference to `sqrt'
prog.c:(.text+0x26a): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
0 0
-----------Re-judge-----------
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()

{
* *** ** *** * * ** ** * *** ** ****** ** ***

* ** ** ** ** **** *** * * %2f ***** * **** * * ** * * *
* ***** *** ** * *** ** * ** = (b*b-4*a*c);
** ** ** ** * * ** = (-b + sqrt(D))/(2*a);
* **** ** ** * *** ** * = (-b - sqrt(D))/(2*a);
** * *** ** ** * * **** = -b/(2*a);
* *** * * ** *** * ***** * * =sqrt(-D)/(2*a);

* ** * * * **** * * (D==0)
***** **** ** **** *** * *
* * * ** * * *** * ** * * * **** * **** * **** * of %.2fx^2 + %.2fx + %.2f = 0 are real and * * ******** **
* *** * *** ******* ** ** *** * ***** *** * *** = x2 = %.2f",x);
* ** *** ** ****** * ***
* ** * * * ** ** * if (D>0)
****** * **** * ***** **
** *** * * ** * * * * ******** * * * * * * * * * of %.2fx^2 + %.2fx + %.2f = 0 are real and ** **** **
**** ** *** * ** ** ** ** * **** ** * ** * = %.2f\n",x);
* * * * * * ** * * * * * * * * *** * * * = %.2f",xx);
** * ** * ***** *******
* *** ****** **** * *
* * * **** * * * ****
** * * *** * * ** * *** * * * * * * ** ** * * ** of %.2fx^2 + %.2fx + %.2f = 0 are complex and ***** ** ** * **
* *** ** *** *** * *** ** ** * *** * ** * * = ** * * ** * *** **
* * * ** * ** ** * ** ********** *** **** ** ** ***** ** ** * = *** * * * ** * * * ***
* * * * ** *** **

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

}
answered by (-249 points)
0 0
/tmp/cckgLAYq.o: In function `main':
prog.c:(.text+0x87): undefined reference to `sqrt'
prog.c:(.text+0xd5): undefined reference to `sqrt'
prog.c:(.text+0x13e): undefined reference to `sqrt'
collect2: error: ld returned 1 exit status
Welcome to Peer-Interaction Programming Learning System (PIPLS) LTLab, National DongHwa University
English 中文 Tiếng Việt
IP:172.69.6.143
©2016-2025

No related questions found

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