字母异位词分组

class Solution {
public:
    vector<vector<string>> groupAnagrams(vector<string>& strs) {
        std::vector<std::vector<std::string>>groups;
        if (strs.empty()) {
            return groups;
        }
        groups.emplace_back(std::vector<std::string>{ strs[0] });
        int size = strs.size();
        for (int i = 1;i < size;i++) {
            bool found = false;
            for (auto &vec : groups) {
                const std::string &first_str = vec[0];
                if (is_anagram(first_str, strs[i])) {
                    vec.emplace_back(strs[i]);
                    found = true;
                    break;
                }
            }
            if (!found) {
                groups.emplace_back(std::vector<std::string>{ strs[i] });
            }
        }
        return groups;
    }
    bool is_anagram(const std::string &one, const std::string &other) {
        int size = one.size();
        if (other.size() != size) {
            return false;
        }
        int i = 0;
        memset(fingerprint_, 0, sizeof(fingerprint_));
        for (;i < size;i++) {
            ++fingerprint_[one[i] - 'a'];
        }
        for (i = 0;i < size;i++) {
            --fingerprint_[other[i] - 'a'];
        }
        for (i = 0;i < size;i++) {
            if (fingerprint_[one[i] - 'a']) {
                return false;
            }
        }
        return true;
    }
private:
    int fingerprint_[26];
};

​​https://github.com/wangzhicheng2013/leetcode/tree/main/leetcode​​