1079. Letter Tile Possibilities

[흑화뉴비(coderhs)]

class Solution:

    def numTilePossibilities(self, tiles: str) -> int:

        letters = set()

        visit = [0 for _ in range(len(tiles))]

        def dfs(cur, visit, letters):

            for i in range(len(tiles)):

                if visit[i] == 0 and cur + tiles[i] not in letters:

                    letters.add(cur + tiles[i])

                    visit[i] = 1

                    dfs(cur + tiles[i], visit, letters)

                    visit[i] = 0

       

        dfs("", visit, letters)

        return len(letters)

만만한 백트래킹 문제만 골라서 푸는 나..