Sequential digits

Enumeration

65.3% acceptance

Feb 25, 2026

2916

178

An integer has sequential digits if and only if each digit in the number is one more than the previous digit. Return a sorted list of all the integers in the range [low, high] inclusive that have sequential digits.

Solution

Rust

Time O(n³)

Space O(n)

LeetCode

solution.rs

impl Solution {
  pub fn sequential_digits(low: i32, high: i32) -> Vec<i32> {
    let mut result = vec![];
    // Generate all sequential digit numbers in order of length
    for len in 2..=9usize {
      for start in 1..=(10 - len) {
        let mut num = 0i32;
        for d in start..(start + len) {
          num = num * 10 + d as i32;
        }
        if num >= low && num <= high {
          result.push(num);
        }
      }
    }
    result
  }
}