What to say, word for word

say

• Let me restate the problem to make sure I have it right.
• How large can n be? Roughly thousands, or millions?
• Can the input be empty? Can it have negatives or duplicates?
• If there is no valid answer, what should I return?
• Is the input sorted, or should I not assume that?

say

• Let me work through a small example by hand first.
• For this input I expect this output. Does that match what you have in mind?

say

• The simplest approach that works is to try every pair. That is O(n²).
• I will start from this and look for the repeated work.
• Should I code this first, or look for a faster approach?

say

• Here is my plan in three steps. Does it sound right to you before I code it?
• This should take O(n) time and O(n) space. I am fine with that trade-off unless memory matters here.

say

• I am thinking about whether sorting helps here.
• The slow part is this inner loop. Can I remember what I have already seen?
• This looks like a sliding window, because we need the best contiguous subarray.

say

• Can I take a minute to think quietly?
• I am stuck on how to avoid checking every pair. Let me try a different example.
• Here is what I know so far, and here is the part I can't see yet.

say

• That is a good point. So if the array is sorted, I can move two pointers inward.
• Let me make sure I understand the hint: you mean I should store the counts first?
• Thank you, that helps. Let me rework the plan with that.

say

• I will write the steps as comments first, then fill them in.
• This loop moves the right pointer and grows the window.
• I will use a helper method here to keep the main method short.

say

• Before I call it done, let me dry run it on the example.
• Now the edge cases: an empty array, a single element, and all duplicates.
• At this step, left is 0 and right is 2, so the sum is 9. That matches.

say

• I see a bug here: this loop goes one step too far. Let me fix the bound.
• You are right, that fails for an empty input. I will add a check at the top.
• Good catch. The sum can overflow an int, so I will use a long.

say

• Let n be the length of the array.
• Time is O(n log n) because of the sort. The scan after it is O(n).
• Space is O(n) for the map. HashMap lookups are O(1) on average; with Integer keys, Java 8 and later keep the worst case at O(log n).

say

• I am not sure about that. My guess is this, and here is how I would check it.
• I have not used that before, but I would expect it to work like this.

say

• What does a normal week look like for someone in this team?
• What would you expect a new engineer to own in the first three months?