Merge pull request neetcode-gh#2037 from saip7795/sp/word-search

Create: 0079-Word-Search.rb

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