Check if The Number is Fascinating
The code is a solution to check if the number n
is fascinating or not.
Understanding the Code
Define a Helper Function: The helper function
pan
takes a stringnum
as input. It checks if the sorted list of characters innum
is exactly["1","2","3","4","5","6","7","8","9"]
. If it is, the function returnsTrue
, indicating thatnum
contains all the digits from 1 to 9 exactly once. Otherwise, it returnsFalse
.Concatenate the Numbers: Outside the helper function,
n
is concatenated with2 * n
and3 * n
to form a single string.Check for Fascinating Number: Finally, the concatenated string is passed to the
pan
function, and its result is returned.
Solution


Key Takeaways
 The code makes use of a helper function to perform the specific check for the fascinating number condition.
 It employs string concatenation and sorting to determine whether the concatenated number meets the required conditions.