LeetCode 389. Find the Difference

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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题目：给你两个字符串都由小写字母组成，t是由s打乱然后再加上一个在随机位置的字母，找到这个添加到t的字母

 

class Solution {
public:
    char findTheDifference(string s, string t) {
        map<char, int> map;
        for (auto &e : t)
        {
            ++map[e];
        }
        for (auto &e : s)
        {
            --map[e];
        }
        for(auto &e:map)
        {
            if(e.second==1)return e.first;
        }
        return 0;
    }
};