Point72·Data Scientist·Technical Phone Screen
- Given an array of circle pairs where each circle is defined by (x, y, r), classify each pair as IDENTICAL, CONCENTRIC, TOUCHING_EXTERNALLY, TOUCHING_INTERNALLY, INTERSECTING, or DISJOINT. Coordinates and radii are integers up to 1e9, and N can be up to 2e5. You must avoid floating-point errors, handle degenerate cases like r=0, and explain your time and space complexity.
“My first instinct was to just compute Euclidean distance and compare, which the interviewer immediately flagged.”