290. Word Pattern ---E

Q:

Given a pattern and a string str, find if str follows the same pattern.

Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in str.

Example 1:

Input: pattern = "abba", str = "dog cat cat dog"
Output: true

Example 2:

Input:pattern = "abba", str = "dog cat cat fish"
Output: false

Example 3:

Input: pattern = "aaaa", str = "dog cat cat dog"
Output: false

Example 4:

Input: pattern = "abba", str = "dog dog dog dog"
Output: false

Notes:
You may assume pattern contains only lowercase letters, and str contains lowercase letters that may be separated by a single space.

A:

Two hashMap

学到的： split string into words

        string str

        vector<string> vec;
        istringstream iss(str);
        for(string s; iss >> s; )
            vec.push_back(s);

class Solution {
public:
    bool wordPattern(string pattern, string str) {
        vector<string> vec;
        istringstream iss(str);
        for(string s; iss >> s; )
            vec.push_back(s);
        
        unordered_map<char,string> map1;
        unordered_map<string,char> map2;
        if(pattern.length() != vec.size())
            return false;
        for(int i = 0;i<pattern.length();++i){
            char ch = pattern[i];
            string word = vec[i];
            if(map1.find(ch) == map1.end()){
                map1[ch] = word;
            }else{
                if(map1[ch] != word)
                    return false;
            }
            if(map2.find(word) == map2.end()){
                map2[word] = ch;
            }else{
                if(map2[word] != ch)
                    return false;
            }
        }
        return true;
    }
};

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