Count Lattice Points Inside a Circle

From LeetCode. Lattice point counting. Solve the geometry problem "Count Lattice Points Inside a Circle".

Difficulty

medium

Companies

Not listed

Topic

Circlesgeometry circles

Examples

Input: [1,2,3]

Output: 0

Input: [2,3,4]

Output: 0

Hints

Since radius ≤ 100, bounding box is at most 200×200 per circle. Brute-force over integer x, y in [cx-r, cx+r] × [cy-r, cy+r].

Check each candidate point with squared distance: (x-cx)² + (y-cy)² ≤ r². No floating point needed.

Multiple circles may overlap — use a Set keyed as "x,y" to deduplicate points. Points exactly on circumference (== r²) count as inside.

Count Lattice Points Inside a Circle

**From LeetCode.** Lattice point counting. Solve the geometry problem "Count Lattice Points Inside a Circle".