Determine if two strings are close

Hash Table String Sorting Counting

54.2% acceptance

Feb 25, 2026

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Two strings are considered close if you can attain one from the other using: Operation 1: Swap any two existing characters. Operation 2: Transform every occurrence of one existing character into another existing character, and do the same with the other character. Given two strings, word1 and word2, return true if word1 and word2 are close.

Solution

Rust

Time O(n log n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn close_strings(word1: String, word2: String) -> bool {
    let mut f1 = [0i32; 26];
    let mut f2 = [0i32; 26];
    for b in word1.bytes() {
      f1[(b - b'a') as usize] += 1;
    }
    for b in word2.bytes() {
      f2[(b - b'a') as usize] += 1;
    }
    // Same character presence
    for i in 0..26 {
      if (f1[i] == 0) != (f2[i] == 0) {
        return false;
      }
    }
    // Same multiset of frequencies
    let mut v1: Vec<i32> = f1.into_iter().filter(|&x| x > 0).collect();
    let mut v2: Vec<i32> = f2.into_iter().filter(|&x| x > 0).collect();
    v1.sort_unstable();
    v2.sort_unstable();
    v1 == v2
  }
}