Question

i need help with a C code i'll write the specifications in the comments

Answer 1

1) i'm only allowed to use int, printf, scanf, getch, if/else, and %
2) the user inputs a number and the code will say if it's prime or not prime

if you will post full codes please explain them simply for me :D

Answer 2

hmmm
for/while loop not allowed ?

Answer 3

OK That's easy, writing your code right now !

Answer 4

@ganeshie8 for/while not allowed

@Jeet.in pls explain later :)

Answer 5

sure, @lgbasallote is goto statement allowed?

Answer 6

depends...how will it be used??

Answer 7

OK i won't be needing it

Answer 8

ahh...so how?

Answer 9

what are these codes :O

Answer 10

you used other codes :(

Answer 11

recursion !!

Answer 12

recursion?

Answer 13

Well do you know what's recursion?

Answer 14

no

Answer 15

Or should I give you a primer?

Answer 16

i'm only allowed to use int, printf, scanf, getch, if/else, and %

Answer 17

Recursion is a programming technique that allows the programmer to express operations in terms of themselves. In C, this takes the form of a function that calls itself. A useful way to think of recursive functions is to imagine them as a process being performed where one of the instructions is to "repeat the process". This makes it sound very similar to a loop because it repeats the same code, and in some ways it is similar to looping. On the other hand, recursion makes it easier to express ideas in which the result of the recursive call is necessary to complete the task. Of course, it must be possible for the "process" to sometimes be completed without the recursive call. One simple example is the idea of building a wall that is ten feet high; if I want to build a ten foot high wall, then I will first build a 9 foot high wall, and then add an extra foot of bricks. Conceptually, this is like saying the "build wall" function takes a height and if that height is greater than one, first calls itself to build a lower wall, and then adds one a foot of bricks.

Answer 18

we're not allowed to loop!! :(

Answer 19

@lgbasallote I only used int, printf, scanf, getch, if/else, and %. recursion is a technique, not a syntax !

Answer 20

like i said..loop is not allowed...

Answer 21

also what is this
soln=checkPrime(num)

and


if((num%i)==0 && i <num)
{
i++;
checkPrime(num);
return 0;

Answer 22

No looping Used :) do you see WHILE DO-WHILE or FOR, GOTO-LABEL in my code? It strictly adheres to your question !

Answer 23

uhmm?

Answer 24

yup. and that's a function i.e. breaking the code into smaller parts !

Answer 25

Read this: http://www.cprogramming.com/tutorial/lesson4.html

Answer 26

Well don't I deserve some medals? Clicking the top right button with a zero on it helps !

Answer 27

@lgbasallote
try this :

#include<stdio.h>

main()
{
int n, c = 2;

printf("Enter a number to check if it is prime\n");
scanf("%d",&n);

check_factor:
if ( n%c == 0 )
{
printf("%d is not prime. %d\n", n, c);
goto last;
}
c++;

if (c <= n-1) {
goto check_factor;
}

if ( c == n )
printf("%d is prime.\n", n);

last:
return 0;
}

Answer 28

Thanks @ganeshie8 !

Answer 29

what does check_factor mean?

Answer 30

it is a label name.
we can label any part of the code.

il try to comment the whole code.. wait ;)

Answer 31

yay thanks

Answer 32

@lgbasallote make sure you understand @ganeshie8 's method and don't just copy ! You need to learn how to code correctly, submitting assignments won't lead you anywhere ;)

Answer 33

hah lol of course..im not interested in the code...im just interested to know how it applies

Answer 34

what i really need is that fibonacci code which i still dont get :/ im hoping to get some clue from here

Answer 35

hmm speaking of which maybe i can ask for an explanation of that code later hmm

Answer 36

#include<stdio.h>

main()
{
int n, c; /* input number, counter checking factors */

printf("Enter a number to check if it is prime\n");
scanf("%d",&n);

check_factor: /* just a label. section of code to check if c is a factor of n */
if ( n%c == 0 )
{
printf("%d is not prime. %d\n", n, c);
goto last;
}
c++; /*increment factor counter c */

if (c <= n-1) { /*jump to check_factor until c is less than n*/
goto check_factor;
}

if ( c == n ) /*we are here still. we didnt jump to last after checking factor for every number < n. means its a prime ! */
printf("%d is prime.\n", n);

last:
return 0;
}

Answer 37

hmm..correct me if im wrong but you used loop?

Answer 38

@lgba ping @shubhamsrg he is good in fibonacci :)

Answer 39

wait...im gonna post a code here (it's not the fibonacci)

Answer 40

i used a jump statement : "goto"

* to jump to top if c < n

Answer 41

okay here's a code we did for testing odd or even...this prime or not prime is a seatwork together with this one


#include <stdio.h>
#include <stdlib.h>
#include<conio.h>

main()
{
int a, b;
printf("Enter a number: \t");
scanf("%d", &a);
b = a%2;
if (b==0)
{
printf("The number is even");
}
else
{
printf("The number is odd");
}

getch();
}

so maybe the prime or not prime might look like that?

Answer 42

btw this was what i meant by the specification..a real simple one :)

Answer 43

Nope, prime is a much more complex process !

Answer 44

the hint my teacher gave us was using modulo

Answer 45

yup were using modulo arithmetic that's the % symbol

Answer 46

hmm i dont think this is possible using those simple codes only eh?

Answer 47

yup ! true your teacher wanted to test your intelligence !

Answer 48

lol that tricky !@#$% haha jkjk

Answer 49

yup ! actually it's not your fault. Your teacher should have taught you the basics first, he/she seems to be skipping topics !