Make string a subsequence using cyclic increments

Two Pointers String

65.7% acceptance

Feb 25, 2026

878

You are given two 0-indexed strings str1 and str2. In an operation, you select a set of indices in str1, and for each index i in the set, increment str1[i] to the next character cyclically. That is 'a' becomes 'b', 'b' becomes 'c', and so on, and 'z' becomes 'a'. Return true if it is possible to make str2 a subsequence of str1 by performing the operation at most once, and false otherwise. Note: A subsequence of a string is a new string that is formed from the original string by deleting some (possibly none) of the characters without disturbing the relative positions of the remaining characters.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn can_make_subsequence(str1: String, str2: String) -> bool {
    let s1 = str1.as_bytes();
    let s2 = str2.as_bytes();
    let mut j = 0;
    for &c in s1 {
      if j < s2.len() && (c == s2[j] || (c - b'a' + 1) % 26 + b'a' == s2[j]) {
        j += 1;
      }
    }
    j == s2.len()
  }
}