integer to bcd

bcd.c

/*
 * Show Integer To BCD-code 
 * - Tokkenizer function makes input array with 10 below Integer.
 * - toBin function shows binary code.
 */

//
void tokkenizer(int n){
    int i ;
    int arr[20] = {0,} ;
    char r[20] =  {0,} ;
    i = 0 ;
    if( n == 0 ){
        printf("0000") ;
        return ;
    }
    while ( n/10 != 0 || n % 10 != 0)
    {
        arr[i] = n % 10 ;
        n = n / 10 ;
        i ++ ;
    }
    n = i ;
    while( i >=  0 )
    {
        r[n-i] = arr[i-1] ;
        i-- ;
    }

    for(int j = 0 ; j < n ; j++ )
    {
        toBin((int)r[j]) ;
        if ( j != n - 1 ){
            printf("_") ;
        }
    }
}

// below 10 input show binary --> 0000 
void toBin(int n){
    int i ;
    int arr[4] = {0,} ;
    char r[4] =  {0,} ;
    i = 0 ;

    while ( n/2 != 0 || n % 2 != 0)
    {
        arr[i] = n % 2 ;
        n = n / 2 ;
        i ++ ;
    }

    i = 3 ;
    while( i >=  0 )
    {
        r[3-i] = arr[i] ;
        i-- ;
    }

    for(int j = 0 ; j < 4 ; j++ )
    {
        printf("%d", r[j]) ;
    }
}