0 like 1 dislike
12k 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 | 12k 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:172.70.126.8
©2016-2025

No related questions found

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