Nearest Neighbouring City

Problem Overview

• For each queried city, return the nearest city sharing its x or y coordinate by Manhattan distance; if none, return "NONE".
• Input: city list [name, x, y] and query names; up to 1e5 cities and 1e5 queries; coordinates up to 1e9; names and coordinates are unique.
• Output: the nearest city name per query.
• Context: cities placed on a Cartesian grid with integer coordinates.
• From Akuna interviews; a common coding interview problem and interview question.