290. 单词模式 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.

public class Solution {
    public bool WordPattern(string pattern, string str) {
		string[] strArr = str.Split(' ');
		if (pattern.Length != strArr.Length || (pattern.Length == 0 && str.Length == 0)) {
			return false;
		}
		Dictionary<char, string> dict = new Dictionary<char, string>();
		for (var i = 0; i < pattern.Length; i++) {
			if (dict.ContainsKey(pattern[i]) || dict.ContainsValue(strArr[i])) {
				string s = null;
				dict.TryGetValue(pattern[i], out s);
				if (s == strArr[i]) {
					continue;
				} else {
					return false;
				}
			} else {
				dict[pattern[i]] = strArr[i];
			}
		}
		return true;
    }
}

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