290. Word Pattern

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.

Examples:

1. pattern = "abba", str = "dog cat cat dog" should return true.
2. pattern = "abba", str = "dog cat cat fish" should return false.
3. pattern = "aaaa", str = "dog cat cat dog" should return false.
4. pattern = "abba", str = "dog dog dog dog" should return false.

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

Credits:
Special thanks to @minglotus6 for adding this problem and creating all test cases.

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用Map做就好

public class Solution {    public boolean wordPattern(String pattern, String str) {        char [] p = pattern.toCharArray();        String [] s = str.split(" ");        HashMap<Character,String> maps =  new HashMap<> ();        if(p.length!=s.length)return false;        for(int i = 0;i<p.length;i++){            if(!maps.containsKey(p[i])){                if(maps.containsValue(s[i]))return false;                maps.put(p[i],s[i]);            }else{                if(!maps.get(p[i]).equals(s[i]))return false;            }        }        return true;    }}