Algorithm-1

Hello everyone. I have taken this question from hackerrank and posted solution for it.
And hope that it will be helpful for you.

Problem Tittle:- Beautiful days at movies
Description:-
Lily likes to play games with integers. She has created a new game where she determines the difference between a number and its reverse. For instance, given the number 12 , its reverse is 21 Their difference is 9 . The number is 120 ,reversed is 21 , and their difference is 99
.
She decides to apply her game to decision making. She will look at a numbered range of days and will only go to a movie on a beautiful day.
Given a range of numbered days, [i...j] and a number k , determine the number of days in the range that are beautiful. Beautiful numbers are defined as numbers where {i-reverse(i)} is evenly divisible by K. If a day's value is a beautiful number, it is a beautiful day. Print the number of beautiful days in the range.


Input Format:-
A single line of three space-separated integers describing the respective values of i,jand k;

Constraints:-
1<=j<=2*(10^6)
1<=k<=2*10^9

Output Format:-
Print the number of beautiful days in the inclusive range between i and j;

Sample Input
20 23 6

Sample Output
2

Explanation
Lily may go to the movies on days 20,21,22 and 23 We perform the following calculations to determine which days are beautiful:

* Day 20 is beautiful because the following evaluates to a whole number (|20-02|)/6=18/6=3.

* Day 21 is not beautiful because the following doesn't evaluate to a whole number (|21-12|)/6=9/6=1.5.

* Day 22 is beautiful because the following evaluates to a whole number (|22-22|)/6=0/6=0.

* Day 23 is not beautiful because the following doesn't evaluate to a whole number (|23-32|)/6=9/6=1.5.

Only two days,20 and 22, in this interval are beautiful. Thus, we print 2 as our answer.

Solution:-
//this function will return the reverse of number n.
 int reverse(int n)
    {
            int r;
    int rev=0;
         while(n!=0)
            {
                r=n%10;
                n=n/10;
                rev=rev*10+r;
               
            }
        return rev;
    }
    //this function will print the number of beautiful days.
     void beautifulDays(int i, int j, int k) {
        int num,count=0;
 
      for(int n=i;n<=j;n++)
        {
           rev=reverse(n);
           
             if(((n-rev)%k)==0)
                 count++;
           
           }
        print(count);
    }

//So our required output(number of beautiful days) is stored in 'count' variable which is printed.