Letter Tile Possibilities
You have n tiles, where each tile has one letter tiles[i] printed on it.
Return the number of possible non-empty sequences of letters you can make using the letters printed on those tiles.
Example 1
Input
tiles = "AAB"Output
8The possible sequences are "A", "B", "AA", "AB", "BA", "AAB", "ABA", and "BAA".
Example 2
Input
tiles = "AAABBC"Output
188There are 188 possible non-empty sequences that can be made from the letters in
tiles.Constraints
- 1 <= tiles.length <= 7
- tiles consists of uppercase English letters.