Two Circles — Solution & Editorial
Compare the SQUARED center distance against (r1+r2)² and (r1−r2)² — everything stays in exact integers, and touching counts as overlap.
Complexity: O(1)
Compare the SQUARED center distance against (r1+r2)² and (r1−r2)² — everything stays in exact integers, and touching counts as overlap.
Complexity: O(1)