Added solution for add and search word

Author: avidLearnerInProgress

add_and_search_word.cpp

@@ -0,0 +1,46 @@
+class WordDictionary {
+public:
+    /** Initialize your data structure here. */
+    vector<WordDictionary* > children;
+    bool isEndOfWord;
+    
+    WordDictionary() {
+        this->isEndOfWord = false; //determine end of word
+        this->children = vector<WordDictionary* >(26, nullptr); //for each node, there are 26 possibilities of character in children
+    }
+    
+    /** Adds a word into the data structure. */
+    void addWord(string word) {
+        auto current_dict = this;
+        for(auto const c : word) {
+            if(current_dict->children[c - 'a'] == nullptr) //check if the current char exist in the Trie
+                current_dict->children[c - 'a'] = new WordDictionary(); //initialize a new dictionary for each possible children
+            current_dict = current_dict->children[c - 'a']; //increment this pointer
+        }
+        current_dict->isEndOfWord = true; //set the flag to true to determine end of word
+    }
+    
+    /** Returns if the word is in the data structure. A word could contain the dot character '.' to represent any one letter. */
+    bool search(string word) {
+        
+        auto current_dict = this;
+        for(int i=0; i<word.length(); i++) {
+            auto c = word[i];
+            if(c == '.'){ //iterate through all the possibilities for this edgecase
+                for(auto ch : current_dict->children)
+                    if(ch && ch->search(word.substr(i+1))) return true;
+                return false;
+            }
+            if(current_dict->children[c - 'a'] == nullptr) return false;
+            current_dict = current_dict->children[c - 'a']; //increment this pointer
+        }
+        return current_dict && current_dict->isEndOfWord;
+    }
+};
+
+/**
+ * Your WordDictionary object will be instantiated and called as such:
+ * WordDictionary* obj = new WordDictionary();
+ * obj->addWord(word);
+ * bool param_2 = obj->search(word);
+ */