Length of the longest alphabetical continuous substring

String

60.3% acceptance

Feb 25, 2026

552

An alphabetical continuous string is a string consisting of consecutive letters in the alphabet. In other words, it is any substring of the string "abcdefghijklmnopqrstuvwxyz". For example, "abc" is an alphabetical continuous string, while "acb" and "za" are not. Given a string s consisting of lowercase letters only, return the length of the longest alphabetical continuous substring.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn longest_continuous_substring(s: String) -> i32 {
    let s = s.as_bytes();
    let mut ans = 1;
    let mut len = 1;
    for i in 1..s.len() {
      if s[i] == s[i - 1] + 1 {
        len += 1;
        ans = ans.max(len);
      } else {
        len = 1;
      }
    }
    ans
  }
}