leetcode - 389. Find the Difference

You are given two strings s and t.

String t is generated by random shuffling string s and then add one more letter at a random position.

Return the letter that was added to t.

 

Example 1:

Input: s = "abcd", t = "abcde"
Output: "e"
Explanation: 'e' is the letter that was added.

Example 2:

Input: s = "", t = "y"
Output: "y"

 

문제 : String s, t 의 다른 문자를 찾아라

풀이

class Solution {
    public char findTheDifference(String s, String t) {
        
        int[] alphaS = new int[26];
        int[] alphaT = new int[26];
        for(char ch : s.toCharArray()){
            alphaS[ch-'a']++;
        }
        for(char ch : t.toCharArray()){
            alphaT[ch-'a']++;
        }
        
        char ch = ' ';
        for(int i=0;i<26;i++){
            if(alphaS[i] != alphaT[i]) return (char)(i+(int)'a');
        }
        
        return ch;
    }
}