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C/C++ Program for Lucky Numbers.

program solution

#include <stdio.h>

#define bool int


/* Returns 1 if n is a lucky no. ohterwise returns 0*/

bool isLucky(int n)


    static int counter = 2;


    /*variable next_position is just for readability of the program we can remove it and use n only */

    int next_position = n;

    if(counter > n)

        return 1;

    if(n%counter == 0)

        return 0;     


    /*calculate next position of input no*/

    next_position -= next_position/counter;



    return isLucky(next_position);



/*Driver function to test above function*/

int main()


    int x = 5;

    if( isLucky(x) )

        printf("%d is a lucky no.", x);


        printf("%d is not a lucky no.", x);




5 is not a lucky no.

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