Description
Given n types of stickers (each with lowercase letters) and a target string, return the minimum number of stickers needed to spell target, or -1 if impossible.
Examples
Input:
stickers = ["with","example","science"], target = "thehat"Output:
3Explanation:
Use 'with' twice and 'example' once.
Input:
stickers = ["notice", "possible"], target = "basicstep"Output:
-1Explanation:
Spelling 'basicstep' requires letters 'b' and 'p' which do not appear in either 'notice' or 'possible'. Since these letters cannot be obtained from any sticker, the task is impossible, returning -1.
Input:
stickers = ["control", "heart", "madle"], target = "mother"Output:
3Explanation:
Use 'madle' for 'm', 'control' for 'o' and 't', and 'heart' for 'h', 'e', and 'r'. Each sticker is used once for a total of 3 stickers.
Constraints
- •
n == stickers.length - •
1 ≤ n ≤ 50 - •
1 ≤ stickers[i].length ≤ 10