LeetCode 862: Shortest Subarray with Sum at Least K
Passing by reference or value
Currently,
std::vector&lt;int&gt; nums

forces callers to pass a copy of the entire vector by value. You could argue that this is actually useful, since your algorithm needs to mutate it (or a copy of it) in-place. My preference is usually to make this copy-step explicit instead:

Pass a const &amp; reference, not a mutable copy
Make a local copy of the vector explicitly, invoking the copy constructor
Mutate your copy.

Spelling
deque_indicies -&gt; deque_indices