10-26 Exercise 3: Find roots of a quadratic equation

Question

Write a program to find roots of a quadratic equation

A 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

Show more...

Comments

We will continue this question in few days

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Everything is fixed. Enjoy your time with The Judge :)

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ANNNNNNNNNNNNNNNNNNNNNNNNNNGRYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

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Your code has newline at the end sometime. You learned this lesson many times!

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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.

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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

Answer 1

Hidden content!
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Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 2

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Comments

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output

Answer 3

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Comments

Case 0: Correct output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Correct output
Case 3: Wrong output

---

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 4

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Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 5

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Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Wrong output
Case 3: Correct output

Answer 6

Hidden content!
#include <stdio.h>
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Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 7

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int a, b, c, D, spD, x1, x2;
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}

Comments

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
 }
 ^

Answer 8

Hidden content!
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#include <stdlib.h>

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}

Comments

Case 0: Correct output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output

---

Case 0: Correct output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output

Answer 9

Hidden content!
#include <stdio.h>
* ***** ***  **   **  * *
int main()
{
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}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 10

Hidden content!
#include <stdio.h>
 *  ** *  *  ***   *
int main()
{
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}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output