Given an array of non-negative integers
a, determine the minimum number of rightward jumps required to jump "outside" the array, starting at position 0, or return zero/null if it is not possible to do so.
A jump from index
i is defined to be an increase in array index by at most
A jump outside is a jump where the index resulting from the jump
i is out-of-bounds for the array, so for 1-based indexing
i>length(a), and for 0-based indexing,
Array = [4,0,2,0,2,0]:
Array = 4 -> You can jump 4 field Array = 0 -> You can jump 0 field Array = 2 -> You can jump 2 field Array = 0 -> You can jump 0 field Array = 2 -> You can jump 2 field Array = 0 -> You can jump 0 field
The shortest path by "jumping" to go out-of-bounds has length
We could jump from
0->2->4->outside which has length
0->4->outside has length
2 so we return
Array = 0 -> You can jump 0 fields Array = 1 -> You can jump 1 field Array = 2 -> You can jump 2 field Array = 3 -> You can jump 3 field Array = 2 -> You can jump 2 field Array = 1 -> You can jump 1 field
In this case, it is impossible to jump outside the array, so we should return a zero/null or any non deterministic value like
Array = 4 -> You can jump 4 field
We can directly jump from index 0 outside of the array, with just one jump, so we return
Due to multiple questions about the return value:
∞ is totally valid, if there is no chance to escape.
Because, if there is a chance, we can define that number.
This is code-golf, so the shortest code in bytes wins!