[数据结构与算法]leetcode算法题--句子中的有效单词数

原题链接：https://leetcode-cn.com/problems/number-of-valid-words-in-a-sentence/

class Solution {
public:
    int countValidWords(string sentence) {
        int t = 0, n = sentence.size(), res = 0;
        while (t < n && sentence[t] == ' ') {
            t++;
        }
        while (t < n) {
            map<char, int> mp;
            int i = t;
            int j = t;
            while (j < n && sentence[j] != ' ') {
                j++;
            }
            t = j;
            while (t < n && sentence[t] == ' ') {
                t++;
            }
            while (i < j) {
                char c = sentence[i];
                if (isdigit(c)) {
                    break;
                } else if (!isalpha(c)) {
                    if (mp.count(c)) {
                        break;
                    } else if (c == '-') {
                        if (i != 0 && i < j - 1 && isalpha(sentence[i - 1]) && isalpha(sentence[i + 1])){
                            mp[c] = 1;
                        } else {
                            break;
                        }
                    } else if (i != j - 1) {
                        break;
                    }
                } 
                i++;
            }
            if (i == j) {
                res++;
            }
        }
        return res;
    }
};