How can I find digits of elements of array in reverse?

Question

Write a recursive C function digit_reverse(.) that takes a positive integer
(up to six digits long) as argument, and returns another integer where the digits
are reversed. For example, if the number passed as argument is 2371, the value
returned will be 1732. Write a main function that uses "digit_reverse" to
determine, if a given number is a palindrome. A palindrome is one which reads
the same forward or backward (like 120021, 234, 5, etc.).
Read a list of positive numbers in an array and print them after reversing their
digits. Further report the palindromes and the number of palindromes.

Answer 1

You can get a last digit for a number by num%10 so that digit will be first digit of reverse number.., you can add further digits by rev*10 + num%10..

Ex:
234
234%10=4, rev=0*10+4=4, num=234/10=23
23%10=3, 4*10+3=43, 23/10=2
2%10=2, 43*10+2=432, 2/10=0

Now you can end loop..
Hope it helps...

Answer 2

#include<stdio.h>
#include<math.h>

int digit_reverse(int A);

int main()
{

int n,i,A[10],reversed[10];

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

printf("The input array is :\n");

for (i=0;i<n;i++)
scanf("%d",&A[i]);

for (i=0;i<n;i++)
printf("%d\n",A[i]);

for (i=0;i<n;i++)
{
reversed[i]=digit_reverse(A[i]); //you are passing single number

//}

printf("Reverse number=%d\n",reversed[i]);
} //added
}

//no need of using array in function..
//corrected way..

int digit_reverse( int A)
{
int reversed=0;

while ( A>0 )
{
reversed=reversed*10+A%10;
A/=10;
}

return reversed;
}

Answer 3

#include<stdio.h>

#include<math.h>

int digit_reverse(int A[]);

int main ()

{

int n,i,A[10],reversed[10];

printf("Enter n:\n");

scanf("%d",n);

printf("%d\n",n);

printf("The input array is :\n");

for (i=0;i<n;i++)

scanf("%d",&A[i]);

for (i=0;i<n;i++)

printf("%d\n",A[i]);

for (i=0;i<n;i++)

{

reversed[i]=digit_reverse(A[i]);

}

printf("Reverse number=%d\n",reversed[i]);

}

int digit_reverse( int A[])

{

int reversed[10],i;

while (A[i]>0)

{

reversed[i]=reversed[i]*10+A[i]%10;

A[i]/=10;

}

return reversed[i];

}

Answer 4

This is my code.It is wrong.Can you tell me what I have to change in this code so that it gives reversed digits array.

Answer 5

Got it,Thank you