Valid Anagram
Given two strings s and t, write a function to determine if t is an anagram of s. 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.
Constraints:
- 1 <= s.length, t.length <= 5 * 10^4
- s and t consist of lowercase English letters
Examples:
Input: s = "anagram", t = "nagaram"
Output: true
Explanation: The string "nagaram" is an anagram of "anagram" because it uses all the same letters in a different order.
Input: s = "rat", t = "car"
Output: false
Explanation: The string "car" is not an anagram of "rat" because it does not use all the same letters.
Solutions
Sorting
This solution works by sorting the characters in each string and comparing the results. If the sorted strings are equal, then the original strings are anagrams of each other.
public boolean isAnagram(String s, String t) {
char[] sArray = s.toCharArray();
char[] tArray = t.toCharArray();
Arrays.sort(sArray);
Arrays.sort(tArray);
return Arrays.equals(sArray, tArray);
}Hash Table
This solution works by using a hash table to count the frequency of each character in the first string, and then decrementing the count for each character in the second string. If any count goes below zero, then the strings are not anagrams.
function isAnagram(s, t) {
if (s.length !== t.length) return false;
const count = {};
for (let char of s) {
count[char] = (count[char] || 0) + 1;
}
for (let char of t) {
if (!count[char] || --count[char] < 0) return false;
}
return true;
}
Follow-up:
What if the input strings contain uppercase letters or special characters?
