Question

Write a program that asks the user to enter a three-digit number, then prints the number with its digits reversed. Do the previous problem with a approach that makes use of the division and modulus operators.

Answer 1

@jango_IN_DTOWN

Answer 2

okay let me post the program

Answer 3

#include<stdio.h>
int main()
{
int n, rev= 0,rem;

printf("Enter a number \n");
scanf("%d",&n);

while (n != 0)
{
rev=rev* 10;
rem=n%10;
rev = rev+rem;
n= n/10;
}

printf("Reverse of entered number is = %d\n", rev);

return 0;
}

Answer 4

this is what i did with two-digit number

Answer 5

it will be same.

Answer 6

The thing is I didn't use the while loop

Answer 7

Can I do something similar? If not, then can you explain to me why you chose the variables that you chose and how you used them? (Preferably with example)

Answer 8

yeah your program will work for 2 digits only

Answer 9

if you want to do the way you did for the 3 digit problem, then i will post the solution. however my method is for any general number.

Answer 10

OK. Can you explain your method?

Answer 11

you may write the program and check it is working or not

Answer 12

Well I believe that your one works because I have seen something similar to it on another website. So I just want to have it explained what each variable stands & why you did certain functions =?

Answer 13

okay let me tell you how i did

Answer 14

OK

Answer 15

do you have pen and paper beside you, it will be very helpful

Answer 16

yes i do

Answer 17

ok.. rem stands for remainder.
when you write rem=n%10, it gives the remainder when the number is divided by 10. i,e, you will get the last digit of n

Answer 18

yes

Answer 19

and rev will be the variable where we want to store the reversed value of n

Answer 20

lets do a dry run. ok??

Answer 21

ok

Answer 22

take n=123. come to the while loop..
obviously n is not equal to 0, so the loop will run
now initially rev was 0
now rev=rev*10=0*10=0
rem=n%10=123%10=3
rev=rev+rem=0+3=0
n=n/10=123/10=12

Answer 23

What do you mean by this:
now initially rev was 0
now rev=rev*10=0*10=0

Answer 24

we declared rev as 0... when we write rev=rev*10, we have rev=0*10=0

Answer 25

oh yes I see now

Answer 26

can you give me a moment while i just process this?

Answer 27

yeah you dry run it

Answer 28

in the 6th line rev will be 3 , i wrote 0 it is wrong

Answer 29

0+3=3

Answer 30

Why did you do rev=0?

Answer 31

And then have rev+rem?

Answer 32

see what you need to do, is bring that 3 at first place, right, for that you need to multiply 3by 100, 2 by 10 and 1 by 1 and just add this thing.. then you get 300+20+1=321. thats we are doing in this while loop

Answer 33

OK

Answer 34

if you need solution by using the method you use, let me post that program. I guees you will understand it better

Answer 35

ok

Answer 36

void main(){
int n,rev,fd,md,ld;
printf("Enter a three digit number\n");
scanf("%d",&n);
fd=n%10;
n=n/10;
md=n%10;
n=n/10;
ld=n;
rev=fd*100+md*10+ld;
printf("\n The reverse of the given number is %d",rev);
}

Answer 37

OK I am going to dry run it

Answer 38

yeah, its the method you used

Answer 39

So let's say i inputted 123

fd = 123%10 = 3
n = 123/10 = 12
md = 123%10 = 3

(does this make sense?)

Answer 40

no you missed something.. n is 12
so md=12%10=2

Answer 41

But if someone enters 123 for n during the line with the scanf, then won't it detect that n=123 or will it just read off with the n=123/10=2?

Answer 42

when you write n=n/10, n vale will not contain the same value as it had previosly

Answer 43

that makes sense now

Answer 44

what language is this C?

Answer 45

Yes it's C

Answer 46

let me do a dry run
take n=123 then fd=123%10=3
n=n/10=123/10=12
md=n%10=12%10=2
n=n/10=12/10=1
ld=n=1
rev=fd*100+md*10+ld=3*100+2*10+1=321 bingo

Answer 47

WOW that is amazing!

Answer 48

its the method you used in case of 2 digits.

Answer 49

Ok gotcha

Answer 50

Thanks tremendously for ur help.. during what times r u available in OS because i take a CS1 class and i usually need help with the hw involving writing c programs

Answer 51

If I am online , I will definitely try to help you. :).

Answer 52

I dont have any fixed time. SO cant tell before hand

Answer 53

Thanks so much :) U are amazing at C!