Ruby Solution for Word Search

Author: saip7795

ruby/0079-word-search.rb

@@ -0,0 +1,37 @@
+def exist(board, word)
+    @rows = board.length
+    @cols = board[0].length
+    @board = board
+    @word = word
+    @path = Set.new()
+
+    set1 = @board.flatten.to_set
+    set2 = @word.split('').to_set
+    return false if !(set1 >= set2)
+
+    def dfs(r,c,i)
+        return true if i == @word.length()
+        return false if (r<0 || c<0 || r >= @rows || c >= @cols || @word[i] != @board[r][c] || @path.include?([r,c]))
+
+        @path.add([r,c])
+
+        result = (dfs(r+1,c,i+1) ||
+                  dfs(r-1,c,i+1) ||
+                  dfs(r,c+1,i+1) ||
+                  dfs(r,c-1,i+1)
+                 )
+        
+        @path.delete([r,c])
+
+        return result
+    end
+
+    (0..@rows-1).each do |r|
+        (0..@cols-1).each do |c|
+            return true if dfs(r,c,0)
+        end
+    end
+
+    return false
+    
+end