Valid Anagram

To solve this coding challenge, the objective is to determine whether one string \( t \) is an anagram of another string \( s \). An anagram is when the characters of one string can be rearranged to form another string, utilizing all the original letters exactly once. For example, "anagram" and "nagaram" are anagrams, but "rat" and "car" are not.

Explanation

  1. Analyzing the Problem :
    • We need to check if two strings (\( s \) and \( t \)) are anagrams.
    • The simplest way to verify is to check if the strings contain the same characters in the same frequency.
    • Constraints include the strings consisting of lowercase English letters and having lengths up to \( 5 \times 10^4 \).
  2. Approach :
    • First, compare the lengths of the two strings. If they are different, they cannot be anagrams.
    • Second, sort both strings and compare them. If they are identical, then \( t \) is an anagram of \( s \).
  3. Optimality and Complexity :
    • Sorting both strings takes \( O(n \log n) \), which is efficient given the constraints.
    • This is efficient and easy to understand, but if one wants a linear-time solution, we can use character frequency counting.
  4. Follow-up for Unicode Characters :
    • If handling Unicode characters, the methodology remains the same. Unicode characters still need to be compared in terms of their frequency and sorted order.

    Detailed Steps in Pseudocode

  5. Check Lengths :
    • If the lengths of \( s \) and \( t \) are not equal, return
      false
      .
  6. Sort and Compare :
    • Convert both strings to character arrays.
    • Sort the character arrays.
    • Compare the sorted arrays.
    • If they are the same, return
      true
      ; otherwise, return
      false
      .
Here is the detailed pseudocode explaining each critical step:
                                            
# Function to check if string t is an anagram of string s
function is_anagram(string s, string t):
    # Step 1: If length of s and t are different, they cannot be anagrams
    if length of s is not equal to length of t:
        return false
    
    # Step 2: Convert strings to lists to sort them
    convert s to list named sorted_s
    convert t to list named sorted_t
    
    # Step 3: Sort the lists
    sort the list sorted_s
    sort the list sorted_t
    
    # Step 4: Compare sorted lists
    if sorted_s is equal to sorted_t:
        return true
    else:
        return false

                                        
This detailed explanation includes everything from the problem understanding to the step-by-step approach to universally applicable pseudocode, ensuring comprehensive clarity on how to tackle the given coding challenge.