C++ | Leetcode C++题解之第387题字符串中的第一个唯一字符

题目：

题解：

class Solution {
public:int firstUniqChar(string s) {unordered_map<char, int> position;queue<pair<char, int>> q;int n = s.size();for (int i = 0; i < n; ++i) {if (!position.count(s[i])) {position[s[i]] = i;q.emplace(s[i], i);}else {position[s[i]] = -1;while (!q.empty() && position[q.front().first] == -1) {q.pop();}}}return q.empty() ? -1 : q.front().second;}
};