最短摘要生成算法

    int FindAbstract(vector<string>&sent,vector<string> &keys,vector<string> &rst)  
    {  
        map<string,int> keyMp;  
        set<string> keySt;  
        int beg = 0,end = 0,s = 0,t = 0,MinLen = 0x7fffffff;  
        queue<int> pos;//将所有关键词的下标放入队列中，当关键词的种类全时，就要从最开始的下标开始遍历  
          
        for(int i=0;i<keys.size();++i)  
            keySt.insert(keys[i]);  
      
        for (;end<sent.size();++end)  
        {  
            if (keySt.find(sent[end])!=keySt.end())  
            {  
                keyMp[sent[end]] +=1;  
                pos.push(end);  
      
                while (keyMp.size() == keys.size())  
                {  
                    beg = pos.front();  
                    pos.pop();  
                    keyMp[sent[beg]] -=1;  
                    if(keyMp[sent[beg]] == 0)  
                        keyMp.erase(sent[beg]);  
                    int span = end - beg +1;  
                    if (span < MinLen)  
                    {  
                        MinLen = span;  
                        s = beg;  
                        t = end;  
                    }  
                }  
            }  
        }  
      
        for (int i=s;i<=t;++i)  
            rst.push_back(sent[i]);  
        return MinLen;  
    }  
    int main()  
    {  
        string strarr[] = {"d","b","e","c","a","b","e","a","e","b","d"};  
        vector<string> cnt;  
        for(int i=0;i<11;++i)  
            cnt.push_back(strarr[i]);  
      
        vector<string> keys;  
        keys.push_back("a");  
        keys.push_back("d");  
        keys.push_back("e");  
        vector<string> rst;  
        cout<<FindAbstract(cnt,keys,rst)<<endl;  
        for(int i=0;i<rst.size();++i)  
            cout<<rst[i]<<" ";  
        return 0;  
    }