https://leetcode.com/problems/shortest-way-to-form-string/description/
A subsequence of a string is a new string that is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (i.e., "ace"
is a subsequence of "abcde"
while "aec"
is not).
Given two strings source
and target
, return the minimum number of subsequences of source
such that their concatenation equals target
. If the task is impossible, return -1
.
Example 1:
1 | Input: source = "abc", target = "abcbc" |
Example 2:
1 | Input: source = "abc", target = "acdbc" |
Example 3:
1 | Input: source = "xyz", target = "xzyxz" |
Constraints:
1 <= source.length, target.length <= 1000
source
andtarget
consist of lowercase English letters.
1 | class Solution { |
Beats 100% and only one submit no debug. It seems finally i grasp some trick? Amazing.