LeetCode242 Valid Anagram

Author: Stefan Su
Create time: 2022-10-31 01:15:00
Location: New York City, NY, USA

Description Easy

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

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

Example 1

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

Example 2

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

Constrains

• 1 <= s.length, t.length <= 5 * 10⁴
• s and t consist of lowercase English letters.

Analysis

Use hash array to store the 26 letters in record array. Once the letter appears in the s, then at the position of that letter, which is also the index in the record, adds one. Keep doing so. Go through each letter in string t as well. But subtract each record[index of letter in t]. After these two for loops are done, check whether there is all zero in record, if yes, these two strings are anagram. If no, they are not.

Solution

• Hash as an array

class Solution(object):
    def isAnagram(self, s, t):
        """
        :type s: str
        :type t: str
        :rtype: bool
        """
        record = [0] * 26
        for _ in s:
            record[ord(_) - ord('a')] += 1

        for _ in t:
            record[ord(_) - ord('a')] -= 1
        
        for _ in record:
            if _ == 0:
                continue
            else:
                return False
        return True

Hopefully, this blog can inspire you when solving LeetCode242. For any questions, please comment below.