0079-word-search.rb

defexist(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
returnfalseif !(set1 >= set2)

defdfs(r,c,i)
returntrueifi == @word.length()
returnfalseif(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])

returnresult
end

(0..@rows-1).eachdo |r|
(0..@cols-1).eachdo |c|
returntrueifdfs(r,c,0)
end
end

returnfalse

end