0 like 1 dislike
10.3k 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 | 10.3k 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:172.70.127.194
©2016-2025

No related questions found

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