Robot return to origin

String Simulation

76.5% acceptance

Feb 20, 2026

2587

753

Given a string moves of R, L, U, D, return true if the robot returns to the origin after all moves, false otherwise.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn judge_circle(moves: String) -> bool {
    let (mut x, mut y) = (0i32, 0i32);
    for c in moves.chars() {
      match c {
        'R' => x += 1,
        'L' => x -= 1,
        'U' => y += 1,
        'D' => y -= 1,
        _ => {}
      }
    }
    x == 0 && y == 0
  }
}