Create 09_word-searchii.cpp

10 October LeetCode Challenge 2021/09_word-searchii.cpp

@@ -0,0 +1,65 @@
+class Trie{
+public:
+    string word;
+    bool is_word=false;
+    Trie* children[26]={NULL};
+};
+
+class Solution {
+private:   
+    Trie* root=NULL;
+
+    void insert(string &s){
+        Trie* temp=root;
+        for(auto &i:s){
+            int k=i-'a';
+            if(temp->children[k]==NULL){
+                temp->children[k]=new Trie;
+            }
+            temp=temp->children[k];
+        }
+        temp->word=s;
+        temp->is_word=true;
+    }
+
+    void dfs(vector<vector<char>>&board, vector<string>&res, Trie* temp, int i, int j){
+
+        if(i<0 || i>=board.size() || j<0 || j>=board[0].size() || board[i][j]=='*' || !(temp->children[board[i][j]-'a']))
+            return;
+
+        temp=temp->children[board[i][j]-'a'];
+
+        if(temp->is_word){
+            res.push_back(temp->word);
+            temp->is_word=false;
+        }
+
+        char temp_char = board[i][j];
+        board[i][j]='*';
+
+        dfs(board, res, temp, i+1, j);
+        dfs(board, res, temp, i, j+1);
+        dfs(board, res, temp, i-1, j);
+        dfs(board, res, temp, i, j-1);
+
+        board[i][j]=temp_char;
+
+        return;
+    }
+
+public:
+    Solution(){
+        root=new Trie;
+    }
+    vector<string> findWords(vector<vector<char>>& board, vector<string>& words) {
+        for(auto &s:words)
+            insert(s);
+        vector<string>res;
+        Trie* temp=root;
+
+        for(int i=0;i<board.size();i++)
+            for(int j=0;j<board[0].size();j++)
+                dfs(board, res, temp, i, j);
+
+        return res;
+    }