290. Word Pattern

class Solution {public:    bool wordPattern(string pattern, string str) {        int len=str.size();        int len0=pattern.size();        int p=0;        int letter[26]={0};        map<string,int> m;        for(int i=0;i<len0;i++)        {            string temp;            while(p<len&&str[p]!=' ')            {                temp.push_back(str[p++]);            }            p++;            if(!temp.size()) return false;            if(m.find(temp)==m.end())             {                if(letter[pattern[i]-'a']==1) return false;                m[temp]=pattern[i]-'a';                letter[pattern[i]-'a']=1;            }            else if(m[temp]!=pattern[i]-'a') return false;        }        if(p<len) return false;        return true;    }};