Minimum number of steps to make two strings anagram

Hash Table String Counting

82.5% acceptance

Feb 25, 2026

2820

121

You are given two strings of the same length s and t. In one step you can choose any character of t and replace it with another character. Return the minimum number of steps to make t an anagram of s. An Anagram of a string is a string that contains the same characters with a different (or the same) ordering.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn min_steps(s: String, t: String) -> i32 {
    let mut cnt = [0i32; 26];
    for b in s.bytes() { cnt[(b - b'a') as usize] += 1; }
    for b in t.bytes() { cnt[(b - b'a') as usize] -= 1; }
    cnt.iter().filter(|&&x| x > 0).sum()
  }
}