leetcode [#389]

目录

• 1. 题目
• 2. 解决方案
• 3. 注意事项

题目

Given two strings s and t which consist of only lowercase letters.

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

Find the letter that was added in t.

Example:
Input:
s = “abcd”
t = “abcde”

Output:
e

Explanation:
‘e’ is the letter that was added.

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解决方案

public class Solution {
    public char findTheDifference(String s, String t) {
        if ((s.length() == 0)) return t.charAt(0);
        char result = 'a';
        List<Character> list = new ArrayList<>();
        for(int i = 0; i < t.length(); i++) list.add(t.charAt(i));
        for(int j = 0; j < s.length(); j++) list.remove((Character) s.charAt(j));
        return list.get(0);
    }
}

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注意事项

1. 将t的每个字符加入arraylist。
2. 遍历s，将s的每个字符从list中取出，剩下的就是新增的。