Code
The highlighted line runs next. The pill shows the live values in the running call.
Recursion tree
Hover a subset in res to find its call
not called yet
running now
paused, waiting on a child call
finished (subset saved)
#k = position in res
Call stack
Top frame runs; the rest are paused
Variables
nums dim cells are outside this call's range (before start)
path one shared list, edited in place by every call
res