Determine if a cell is reachable at a given time

Math

37.2% acceptance

Feb 25, 2026

839

770

You are given four integers sx, sy, fx, fy, and a non-negative integer t. In an infinite 2D grid, you start at the cell (sx, sy). Each second, you must move to any of its adjacent cells. Return true if you can reach cell (fx, fy) after exactly t seconds, or false otherwise. A cell's adjacent cells are the 8 cells around it that share at least one corner with it. You can visit the same cell several times.

Solution

Rust

Time O(1)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn is_reachable_at_time(sx: i32, sy: i32, fx: i32, fy: i32, t: i32) -> bool {
    let dx = (sx - fx).abs();
    let dy = (sy - fy).abs();
    if dx == 0 && dy == 0 { return t != 1; }
    let min_time = dx.max(dy);
    t >= min_time
  }
}