Strobogrammatic number

Hash Table Two Pointers String

47.5% acceptance

Mar 31, 2026

633

1052

Given a string num which represents an integer, return true if num is a strobogrammatic number. A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn is_strobogrammatic(num: String) -> bool {
    let s: Vec<u8> = num.bytes().collect();
    let n = s.len();
    for i in 0..=(n - 1) / 2 {
      let j = n - 1 - i;
      let pair = (s[i], s[j]);
      match pair {
        (b'0', b'0') | (b'1', b'1') | (b'8', b'8') | (b'6', b'9') | (b'9', b'6') => {},
        _ => return false,
      }
    }
    true
  }
}