Formatted question description: https://leetcode.ca/all/1347.html

# 1347. Minimum Number of Steps to Make Two Strings Anagram (Medium)

Given two equal-size strings 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.


Example 4:

Input: s = "xxyyzz", t = "xxyyzz"
Output: 0


Example 5:

Input: s = "friend", t = "family"
Output: 4


Constraints:

• 1 <= s.length <= 50000
• s.length == t.length
• s and t contain lower-case English letters only.

Related Topics:
String

## Solution 1.

// OJ: https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagram/

// Time: O(N)
// Space: O(1)
class Solution {
public:
int minSteps(string s, string t) {
int cnt[26] = {0}, ans = 0;
for (char c : s) cnt[c - 'a']++;
for (char c : t) cnt[c - 'a']--;
for (int n : cnt) {
if (n > 0) ans += n;
}
return ans;
}
};


Java

class Solution {
public int minSteps(String s, String t) {
int length = s.length();
int[] counts = new int[26];
for (int i = 0; i < length; i++) {
char c1 = s.charAt(i), c2 = t.charAt(i);
counts[c1 - 'a']++;
counts[c2 - 'a']--;
}
int steps = 0;
for (int i = 0; i < 26; i++) {
if (counts[i] > 0)
steps += counts[i];
}
return steps;
}
}