Watch 10 video solutions for Letter Tile Possibilities, a medium level problem involving Hash Table, String, Backtracking. This walkthrough by NeetCodeIO has 11,620 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
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: 8 Explanation: The possible sequences are "A", "B", "AA", "AB", "BA", "AAB", "ABA", "BAA".
Example 2:
Input: tiles = "AAABBC" Output: 188
Example 3:
Input: tiles = "V" Output: 1
Constraints:
1 <= tiles.length <= 7tiles consists of uppercase English letters.