Path crossing

Hash Table String

62.6% acceptance

Feb 25, 2026

1552

Given a string path, where path[i] = 'N', 'S', 'E' or 'W', each representing moving one unit north, south, east, or west, respectively. You start at the origin (0, 0) on a 2D plane and walk on the path specified by path. Return true if the path crosses itself at any point, that is, if at any time you are on a location you have previously visited. Return false otherwise.

Solution

Rust

Time O(n)

Space O(n)

LeetCode

solution.rs

use std::collections::HashSet;

impl Solution {
  pub fn is_path_crossing(path: String) -> bool {
    let mut visited: HashSet<(i32, i32)> = HashSet::new();
    let (mut x, mut y) = (0i32, 0i32);
    visited.insert((x, y));
    for c in path.chars() {
      match c {
        'N' => y += 1,
        'S' => y -= 1,
        'E' => x += 1,
        'W' => x -= 1,
        _ => {}
      }
      if !visited.insert((x, y)) { return true; }
    }
    false
  }
}