LeetCode OJ——Word Ladder2

http://oj.leetcode.com/problems/word-ladder-ii/

class Solution {
public:
    vector<vector<string>> findLadders(string start, string end, unordered_set<string> &dict)
    {
        //map <string,string> parentRecord;
        multimap<string ,string> parentRecord;
        queue<pair<string ,int > > wordQueue;
        unordered_set<string> visited;
        wordQueue.push(make_pair(start,1));
        visited.insert(start);

        parentRecord.insert(make_pair(start,"0"));

        int flag = 0;
        int length = 0;
        int flag2 = 0;
        while(!wordQueue.empty())
        {
            string curStr = wordQueue.front().first;
            int curStep = wordQueue.front().second;

            if(flag ==1 )
            { 
                if(curStep != length)
                    break;
            }

            wordQueue.pop();

            for(int i = 0;i<curStr.size();i++)
            {
                if(flag2 == 1)
                {
                    flag2 = 0;
                    break;
                }
                string tmp = curStr;
                for(int j = 0;j<26;++j)
                {
                    flag2 = 0;
                    tmp[i] = j+'a';
                    if(tmp == end)
                    {
                        //    return curStep+1;
                        parentRecord.insert(make_pair(tmp,curStr));
                        flag = 1;
                        length = curStep;
                        flag2 = 1;

                        wordQueue.push(make_pair(tmp,curStep+1));
                        visited.insert(tmp);

                        break;
                    }
                    if(visited.find(tmp) == visited.end() && dict.find(tmp)!=dict.end())
                    {
                        wordQueue.push(make_pair(tmp,curStep+1));
                        visited.insert(tmp);
                        parentRecord.insert(make_pair(tmp,curStr));
                    }
                }
            }
        }

        vector<vector<string> > ansVector;
        ansVector.clear();
        vector<string> onePiece;
        string str1 = end,str2;
        multimap<string,string>::iterator iter;
        int ii = parentRecord.count(end);
        vector<string> another;
        another.clear();

        for(int i = 0;i<ii;i++)
        {    
            str1 = end;
            onePiece.clear();
            another.clear();
            while(1)
            {
                onePiece.push_back(str1);

                iter = parentRecord.find(str1);

                if(  str1 == start)
                {
                    for(int it = onePiece.size()-1;it>=0;it--)
                        another.push_back(onePiece[it]);
                    ansVector.push_back(another);
                    break;
                }
                str2 = (*iter).second;
                if(parentRecord.count(str1)>1)
                    parentRecord.erase(iter);
                str1 = str2;
                
                

            }
        }
     
        return ansVector;

    }
};

在visited那的处理那里弄错了，应该是更广一些。暂时不想改，先这样。

用到了multimap.因为map的话，key是唯一的，只能存储（cog,dog）不能一起存储(cog,dog),(cog,log).