LeetCode 6008. 统计包含给定前缀的字符串

示例 1：
输入：words = ["pay","attention","practice","attend"], pref = "at"
输出：2
解释：以 "at" 作为前缀的字符串有两个，分别是："attention" 和 "attend" 。

示例 2：
输入：words = ["leetcode","win","loops","success"], pref = "code"
输出：0
解释：不存在以 "code" 作为前缀的字符串。
 
提示：
1 <= words.length <= 100
1 <= words[i].length, pref.length <= 100
words[i] 和 pref 由小写英文字母组成

class Solution:
    def prefixCount(self, words: List[str], pref: str) -> int:
        return len([x for x in words if x.startswith(pref)])

class Solution {
public:
    int prefixCount(vector<string>& words, string pref) {
        int n = pref.size(), ans = 0;
        for(auto& w : words)
        {
            if(w.size() < n) continue;
            if(w.substr(0,n) == pref)
                ans++;
        }
        return ans;
    }
};