-00f2134567890-=-=01Create 07_wordSearch.cpp

10 October LeetCode Challenge 2021/07_wordSearch.cpp

@@ -0,0 +1,34 @@
+class Solution {
+public:
+   bool exist(vector<vector<char>> &board, string word) {
+       // checking for all positions
+       for(int i = 0 ; i < board.size() ; ++i)
+           for(int j = 0 ; j < board[0].size() ; ++j)
+               if(dfs(0 , i , j , board , word))
+                   return true;
+       return false;
+   }
+   bool dfs(int index , int x , int y , vector<vector<char>> &board , string &word)
+   {
+       if(index == word.size()) // word exists in matrix
+           return true;
+
+       if(x < 0 or y < 0 or x >= board.size() or y >= board[0].size() or board[x][y] == '.') // boundary check + visited check
+           return false;
+
+       if(board[x][y] != word[index])
+           return false;
+
+       char temp = board[x][y];
+       board[x][y] = '.'; // marking it visited
+
+       // Move in 4 directions[UP , DOWN , LEFT , RIGHT]
+       if(dfs(index + 1 , x - 1 , y , board , word) or dfs(index + 1 , x + 1 , y , board , word) or dfs(index + 1 , x , y - 1 , board , word) or dfs(index + 1 , x , y + 1 , board , word))
+           return true;
+
+       board[x][y] = temp; // backtrack step
+       return false;
+
+   }
+
+};