solved design-add-and...

Author: sangbeenmoon

design-add-and-search-words-data-structure/sangbeenmoon.java

@@ -0,0 +1,63 @@
+import java.util.HashMap;
+import java.util.Map;
+
+class WordDictionary {
+
+
+    Map<Character, WordDictionary> map;
+    boolean isEnd = false;
+
+    public WordDictionary() {
+        map = new HashMap<>();
+    }
+    
+    public void addWord(String word) {
+        char ch = word.charAt(0);
+        WordDictionary node;
+        if (map.containsKey(ch)) {
+            node = map.get(ch);
+        } else {
+            node = new WordDictionary();
+        }
+
+        map.put(ch, node);
+
+        if (word.length() == 1) {
+            node.isEnd = true;
+            return;    
+        }
+
+        node.addWord(word.substring(1));
+    }
+    
+    public boolean search(String word) {
+        if (word.length() == 0) {
+            return isEnd;
+        }
+
+        char ch = word.charAt(0);
+        WordDictionary node;
+
+        if (ch == '.') {
+            for (Map.Entry<Character, WordDictionary> entry : map.entrySet()) {
+                if (entry.getValue().search(word.substring(1))){
+                    return true;
+                }
+            }
+        }
+
+        if (map.containsKey(ch)) {
+            node = map.get(ch);
+            return node.search(word.substring(1));
+        }
+
+        return false;
+    }
+}
+
+/**
+ * Your WordDictionary object will be instantiated and called as such:
+ * WordDictionary obj = new WordDictionary();
+ * obj.addWord(word);
+ * boolean param_2 = obj.search(word);
+ */