Closest pair sum in a sorted array
You're given a sorted array nums and a target t. Among all pairs of distinct positions, find the one whose sum is closest to t.
nums = [1, 3, 4, 7, 10], t = 15
-> 14 # 4 + 10 is closest to 15
Return the closest achievable sum. Aim for time and space, and justify why the pointer you move never skips the best pair.
Show a hint
If the current sum is below the target, only one of the two pointers can raise it. Moving the other pointer strictly moves you away.
Your answer
This one is open-ended. Work it through, then check your reasoning against the full solution.