Merge pull request #2045 from alexprudhomme/0290-word-pattern.cs

Create: 0290-word-patterns.cs

Author: tahsintunan

csharp/0290-word-pattern.cs

@@ -0,0 +1,23 @@
+public class Solution {
+    public bool WordPattern(string pattern, string s) {
+        var words = s.Split(' ');
+        if (words.Length != pattern.Length) return false;
+
+        Dictionary<char,string> charToWord = new Dictionary<char, string>();
+        Dictionary<string, char> wordToChar = new Dictionary<string, char>();
+
+        for (int i = 0; i < pattern.Length; i++) {
+            char c = pattern[i];
+            string w = words[i];
+            if (charToWord.ContainsKey(c) && (charToWord[c] != w)) {
+                return false;
+            }
+            if(wordToChar.ContainsKey(w) && (wordToChar[w] != c)) {
+                return false;
+            }
+            charToWord[c] = w;
+            wordToChar[w] = c;
+        }
+        return true;
+    }
+}