1347. Minimum Number of Steps to Make Two Strings Anagram

Problem

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.

  Example 1:

Input: s = "bab", t = "aba"
Output: 1
Explanation: Replace the first 'a' in t with b, t = "bba" which is anagram of s.

Example 2:

Input: s = "leetcode", t = "practice"
Output: 5
Explanation: Replace 'p', 'r', 'a', 'i' and 'c' from t with proper characters to make t anagram of s.

Example 3:

Input: s = "anagram", t = "mangaar"
Output: 0
Explanation: "anagram" and "mangaar" are anagrams. 

  Constraints:

• 1 <= s.length <= 5 * 10^4

• s.length == t.length

• s and t consist of lowercase English letters only.

Solution (Java)

class Solution {
    public int minSteps(String s, String t) {
        int[] counts = new int[26];
        for (char c : s.toCharArray()) {
            counts[c - 'a']++;
        }
        for (char c : t.toCharArray()) {
            if (counts[c - 'a'] > 0) {
                counts[c - 'a']--;
            }
        }
        return Arrays.stream(counts).sum();
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).