Occurrences after bigram

String

63.9% acceptance

Feb 25, 2026

528

371

Given two strings first and second, consider occurrences in some text of the form "first second third", where second comes immediately after first, and third comes immediately after second. Return an array of all the words third for each occurrence of "first second third".

Solution

Rust

Time O(n)

Space O(n)

LeetCode

solution.rs

impl Solution {
  pub fn find_ocurrences(text: String, first: String, second: String) -> Vec<String> {
    let words: Vec<&str> = text.split_whitespace().collect();
    let mut res = vec![];
    for i in 0..words.len().saturating_sub(2) {
      if words[i] == first && words[i+1] == second {
        res.push(words[i+2].to_string());
      }
    }
    res
  }
}