p0
to 0, p2
to n - 1
, and curr
to 0.curr
is less than or equal to p2
:
nums[curr]
is 0, swap nums[curr]
with nums[p0]
and increment both p0
and curr
.nums[curr]
is 2, swap nums[curr]
with nums[p2]
and decrement p2
.nums[curr]
is 1, increment curr
.curr
is greater than p2
.