2828. Check if a String Is an Acronym of Words

Given an array of strings words and a string s, determine if s is an acronym of words.

The string s is considered an acronym of words if it can be formed by concatenating the first character of each string in words in order. For example, "ab" can be formed from ["apple", "banana"], but it can’t be formed from ["bear", "aardvark"].

Return true if s is an acronym of words, and false otherwise.

class Solution {
public:
    bool isAcronym(vector<string>& words, string s) {
        string res = "";
        for(auto w : words) res.push_back(w[0]);
        return res == s;
    }
};