Substring with Concatenation of All Words

You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of substring(s) in s that is a concatenation of each word in wordsexactly once and without any intervening characters.

For example, given:
s: "barfoothefoobarman"
words: ["foo", "bar"]

You should return the indices: [0,9].
(order does not matter).

下面这段代码只能通过三分之二的测试用例，因为a concatenation of each word in wordsexactly once，我能说题目意思给的不明确么？

网上还有应用“滑动窗口”的时间复杂度为O（n）算法，后面再分析！

class Solution {
public:
    vector<int> findSubstring(string s, vector<string>& words) {
        vector<int> res;
        int wordNum=words.size(),wordLen=words[0].size();
        if(s.size()<wordLen*wordNum)
            return res;
        map<string,int> dic,curWord;
        for(int i=0;i<wordNum;i++)
        {
            dic[words[i]]++;
        }
        for(int i=0;i<s.size()-wordLen*wordNum;i++)
        {
            curWord.clear();
            int count=0;
            for(int j=0;j<wordNum;j++)
            {
                string word=s.substr(i+j*wordLen,wordLen);
                if(dic.find(word)==dic.end())
                    break;
                curWord[word]++;
                count++;
                if(curWord[word]>dic[word])
                    break;
            }
            if(count==wordNum)
                res.push_back(i);
        }
        return res;
    }
};