Problem
Given two strings s and t , write a function to determine if t is an anagram of s.
Example 1:
Input: s = "anagram", t = "nagaram"
Output: true
Example 2:
Input: s = "rat", t = "car"
Output: false
Note:
You may assume the string contains only lowercase alphabets.
Solution
We can compare the frequency of the characters.
import java.util.*;
class Solution {
public static void main(String[] args) {
String s = null, t = "";
System.out.println(solve(s, t));
}
private static boolean solve(String s, String t) {
if(s == null || t == null)
throw new IllegalArgumentException("bad input");
char[] freq = new char[26];
for(char c : s.toCharArray()) {
freq[c - 'a']++;
}
for(char c : t.toCharArray()) {
freq[c - 'a']--;
if(freq[c - 'a'] < 0)
return false;
}
for(int i : freq) {
if(i != 0)
return false;
}
return true;
}
}
The time complexity is O(max(L1, L2)), space complexity is O(max(L1, L2)), where L1 and L2 is the length of the two strings.
