dq
to store pairs of indices and their corresponding scores.score
with the value of nums[0]
since that's the starting point.nums
starting from index 1.
i
, first remove indices from the front of dq
that are out of the current window (i.e., smaller than i-k
).score
to the sum of nums[i]
and the score of the front element of dq
.score
, pop elements from the back of the deque.score
as a pair to the back of the deque.score
of the last element.