240. Print the Digits Forwards
Core1000 ms256 MBSolved by 0%
Print the digits of n in order, one per line, most significant first.
The only easy way to take digits off a number is from the RIGHT, using % 10
and / 10. So the digits come out backwards, and you are asked for them
forwards.
Recursion solves this without reversing anything. Recurse FIRST, then print. The deepest call holds the leftmost digit and finishes first, so the printing happens on the way back up.
This is the clearest demonstration of what the call stack is actually holding, and it is worth writing both orders once to see the difference.
Constraints - `0 ≤ n ≤ 1000000000000000000`
Input
A single line containing one integer n.
Output
Print the digits of n, one per line, in their original order.
Input123
Output1
2
3
Notemust come out forwards, not backwards
Input0
Output0
Noteis a single zero, which must print rather than being skipped
Hints
Four rungs, in order. The last two open once you have submitted an attempt. A wrong one counts.
Hint 1Where to start
Hint 2The approachOpen hint 1 first. This one carries on from it.
Hint 3PseudocodeOpen hint 2 first. This one carries on from it.
Hint 4Full solutionOpen hint 3 first. This one carries on from it.