Queries on number of points inside a circle

Array Math Geometry

86.8% acceptance

Feb 25, 2026

1194

You are given an array points where points[i] = [xi, yi] is the coordinates of the ith point on a 2D plane. Multiple points can have the same coordinates. You are also given an array queries where queries[j] = [xj, yj, rj] describes a circle centered at (xj, yj) with a radius of rj. For each query queries[j], compute the number of points inside the jth circle. Points on the border of the circle are considered inside. Return an array answer, where answer[j] is the answer to the jth query.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn count_points(points: Vec<Vec<i32>>, queries: Vec<Vec<i32>>) -> Vec<i32> {
    queries.iter().map(|q| {
      let (cx, cy, r) = (q[0], q[1], q[2]);
      points.iter().filter(|p| {
        let dx = p[0] - cx;
        let dy = p[1] - cy;
        dx * dx + dy * dy <= r * r
      }).count() as i32
    }).collect()
  }
}