Pattern, m1o2, fxp, elsf, C, gcd

void printArr( int arr[], int n ){

    int index;
    for( index = 0; index < n; ++index )
        printf("%d ", arr[ index ] );

}

int gcd( int a, int b ){

    while( 0 != b ){

        int temp = b;
        b = a % b;
        a = temp;
    }

    return a;
}
int is_serial( int arr[], int n ){

    int digits[10] = {0};
    int *pattern;
    int index, current;
    int length = 0, min = 0;
    int gcdResult = 1, patternLength = 0;

    for( index = 0; index < n; ++index )        // O(n)
        ++digits[ arr[ index ] ];

    for( index = 0; index < 10; ++index ){ //O(1)

        if( 0 < digits[ index ] ){

            if( min == 0 || digits[ index ] < min )
                min = digits[ index ];

            length += digits[ index ];
        }
    }

    gcdResult = gcd( length, min );

    if( 0 != (n % gcdResult ) )
        return 0;

    patternLength = ( length/ gcdResult );
    pattern = (int*)malloc( sizeof(int) * ( patternLength ) );
    // check if malloc failed.

    for( index = 0; index < patternLength; ++index )
        pattern[ index ] = arr[ index ];

    for( index = length, current = 0; index < n; ++index, current = ( ( current + 1 ) % patternLength ) ){

        if( arr[ index ] != pattern[ current ] ){

            free( pattern );
            return 0;
        }
    }

    printf("\n\n the pattern appears %d times : ", length/patternLength);
    printArr( pattern, patternLength );
    free( pattern );
    return 1;
}



int main( int argc, char *argv[] ){

//  int arr[] = {1,2,3,1,1,3,1,1,2,3,1,1,3,1};
//  int n = 14;

    int arr[] = {1,2,3,1,2,3,1,2,3};
    int n = 9;

    int isSerial;
    printf("Arr: " );
    printArr( arr, n );

    isSerial = is_serial( arr, n );

    printf("\n\n is serial : %d ", isSerial );

    getch();
    return 0;
}