0 like 1 dislike
9.6k 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 | 9.6k 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:172.69.58.80
©2016-2025

No related questions found

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