30 Day Challenge Day 15 | Leetcode 720. Longest Word in Dictionary

题解

Easy

方法一：Greedy 贪心算法

class Solution {
public:
    string longestWord(vector<string>& words) {
        string res;
        unordered_set<string> s;
        sort(words.begin(), words.end());
        for(auto& word : words) {
            if(word.size() == 1 || s.count(word.substr(0, word.size()-1))) {
                res = word.size() > res.size() ? word : res;
                s.insert(word);
            }
        }
        return res;
    }
};