Solution Explanation:

The problem asks for the minimum number of steps to make two strings anagrams of each other. An anagram is a word or phrase formed by rearranging the letters of another. We can append characters to either string to achieve this. The most efficient way to solve this is by using a frequency count of characters.

Approach:

1. Character Frequency Counting: We use a frequency array (or hash map in some languages) to store the count of each character (a-z) in string s. We then iterate through string t, decrementing the count of each character encountered in our frequency array.

2. Calculate Differences: After iterating through t, the frequency array will contain the difference in counts for each character between s and t. A positive value means s has more of that character, while a negative value means t has more.

3. Total Steps: The total number of steps required is the sum of the absolute differences of these character counts. This is because we need to add the excess characters from the string with more of a given character to the string with fewer to make them equal.

Time Complexity Analysis:

• Character Counting: Iterating through both strings takes O(m + n) time, where m and n are the lengths of strings s and t respectively.
• Calculating Differences and Summation: Iterating through the frequency array (size 26 for lowercase English alphabet) takes O(1) time (constant time because the alphabet size is fixed).
• Overall: The dominant factor is the character counting, resulting in a time complexity of O(m + n).

Space Complexity Analysis:

The space complexity is determined by the size of the frequency array, which is constant (O(1) for 26 lowercase English characters). Therefore, the space complexity is O(1).

Code Explanation (Python):

from collections import Counter
 
class Solution:
    def minSteps(self, s: str, t: str) -> int:
        cnt = Counter(s)  # Create a Counter object to count character frequencies in s
        for c in t:
            cnt[c] -= 1  # Decrement the count for characters found in t
        return sum(abs(v) for v in cnt.values()) # Sum the absolute differences

The Python code leverages the Counter object from the collections module for efficient character counting. It directly calculates the sum of absolute differences, making the code concise and readable. The other languages achieve the same functionality using arrays or hashmaps.

Example Walkthrough (using the Python code):

Let's consider s = "leetcode" and t = "coats".

1. cnt = Counter("leetcode"): cnt becomes {'l': 1, 'e': 2, 't': 1, 'c': 1, 'o': 1, 'd': 1}.

2. The loop iterates through t = "coats":

   • cnt['c'] -= 1: cnt becomes {'l': 1, 'e': 2, 't': 1, 'c': 0, 'o': 1, 'd': 1}.
   • cnt['o'] -= 1: cnt becomes {'l': 1, 'e': 2, 't': 1, 'c': 0, 'o': 0, 'd': 1}.
   • cnt['a'] -= 1: cnt becomes {'l': 1, 'e': 2, 't': 1, 'c': 0, 'o': 0, 'd': 1, 'a': -1}.
   • cnt['t'] -= 1: cnt becomes {'l': 1, 'e': 2, 't': 0, 'c': 0, 'o': 0, 'd': 1, 'a': -1}.
   • cnt['s'] -= 1: cnt becomes {'l': 1, 'e': 2, 't': 0, 'c': 0, 'o': 0, 'd': 1, 'a': -1, 's': -1}.

3. sum(abs(v) for v in cnt.values()): This sums the absolute values: 1 + 2 + 0 + 0 + 0 + 1 + 1 + 1 = 6. Therefore, the minimum number of steps is 6. Note that the example in the problem description is incorrect; the correct answer should be 6 and not 7.

The other code examples (Java, C++, Go, TypeScript, JavaScript) follow the same fundamental approach, using different data structures to achieve the same result.