🔤 Valid Anagram (Step-by-Step Explanation)

The Valid Anagram problem is a fundamental string problem that checks whether two strings contain the same characters in a different order.

📌 Problem Statement

Given two strings s and t, return true if t is an anagram of s, otherwise return false.

👉 An anagram means both strings have:

Same characters
Same frequency of each character

🔍 Examples

Example 1:
Input: s = "anagram", t = "nagaram"
Output: true

Example 2:
Input: s = "rat", t = "car"
Output: false

🧠 Intuition

To check if two strings are anagrams:

Both strings must have the same length
The frequency of each character must match

🔄 Approach 1 (Sorting Method – Simple)

Step-by-Step:

Sort both strings
Compare them

💻 Python Code

```python id="a1"
def is_anagram(s, t):
return sorted(s) == sorted(t)

print(is_anagram("anagram", "nagaram"))




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⚡ Complexity

Time Complexity: O(n log n)
Space Complexity: O(n)

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🔄 Approach 2 (Frequency Count – Optimal)

Step-by-Step:

1. If lengths are different → return False
2. Count frequency of each character
3. Compare both counts

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💻 Python Code



```python id="a2"
def is_anagram(s, t):
    if len(s) != len(t):
        return False

    count = {}

    for char in s:
        count[char] = count.get(char, 0) + 1

    for char in t:
        if char not in count:
            return False
        count[char] -= 1

    return all(value == 0 for value in count.values())

print(is_anagram("anagram", "nagaram"))

⚡ Complexity

Time Complexity: O(n)
Space Complexity: O(1) (only 26 lowercase letters)

🔥 Why This Works