Given two strings s and t, write a function to determine if t is an anagram of s.
For example,
s = “anagram”, t = “nagaram”, return true.
s = “rat”, t = “car”, return false.
Note:
You may assume the string contains only lowercase alphabets.
Follow up:
What if the inputs contain unicode characters? How would you adapt your solution to such case?
O(2n + 26)
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| public class Solution {
public boolean isAnagram(String s, String t) {
if (s == null || t == null || s.length() != t.length()){return false;}
int[] counts = new int[26];
for (int i = 0; i < s.length(); i++){
counts[s.charAt(i) - 'a']++;
counts[t.charAt(i) - 'a']--;
}
for (int j = 0; j < counts.length; j++){
if (counts[j] != 0){
return false;
}
}
return true;
}
}
|
HashMap solution for the follow up
O(2n)
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| public class Solution {
public boolean isAnagram(String s, String t) {
if (s == null || t == null || s.length() != t.length()) return false;
HashMap<Character,Integer> map = new HashMap<Character, Integer>();
for (int i = 0; i < s.length(); i++){
char cur = s.charAt(i);
if (map.containsKey(cur)){
map.put(cur, map.get(cur) + 1);
}else{
map.put(cur, 1);
}
}
for (int j = 0; j < t.length(); j++){
char Cur = t.charAt(j);
if (map.containsKey(Cur)){
int count = map.get(Cur) - 1;
if (count == 0){
map.remove(Cur);
}else{
map.put(Cur, count);
}
}else{
return false;
}
}
return true;
}
}
|