Adding Simple Solution for Problem - 79 - Word Search

Author: Vanditg

Word_Search/SimpleSolution.py

@@ -0,0 +1,46 @@
+##==================================
+## Leetcode
+## Student: Vandit Jyotindra Gajjar
+## Year: 2020
+## Problem: 79
+## Problem Name: Word Search      
+##===================================
+#
+#Given a 2D board and a word, find if the word exists in the grid.
+#
+#The word can be constructed from letters of sequentially adjacent cell, 
+#where "adjacent" cells are those horizontally or vertically neighboring. 
+#The same letter cell may not be used more than once.
+#
+#Example:
+#
+#board =
+#[
+#  ['A','B','C','E'],
+#  ['S','F','C','S'],
+#  ['A','D','E','E']
+#]
+#
+#Given word = "ABCCED", return true.
+#Given word = "SEE", return true.
+#Given word = "ABCB", return false.
+class Solution:
+    def exist(self, board, word):
+        for i, r in enumerate(board):	#Loop through board
+            for j, value in enumerate(r):	#Loop through r, row basically
+                if value == word[0]:	#Condition-check: If we find the letter 
+                    if self.dfs(i, j, 0, board, word)	#Condition-check: If by applying dfs we find the neighboring word 
+                        return True	#We return True if find the word 
+        return False	#Else We return false
+    def dfs(self, i, j, index, board, word):	#Defining helper method dfs  
+        if index == len(word):	#Condition-check: If index is equal to len(word)
+            return True	#We return True
+        if not (0 <= i < len(board) and 0 <= j < len(board[i])) or board[i][j] != word[index]:	#Condition-check
+            return False	#We return false
+        tmp = board[i][j]	#Initialize tmp board
+        board[i][j] = '+'	#Update the value by '+'
+        for nI, nJ in (i + 1, j), (i - 1, j), (i, j + 1), (i, j - 1):	#For neighboring elements
+            if self.dfs(nI, nJ, index + 1, board, word):	#Condition-check: If by applying dfs we find the word
+                return True	#We return True 
+        board[i][j] = tmp	#Update board values by tmp
+        return True	#We return True