leetcode一题没看明白# JobHunting - 待字闺中
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Distinct Subsequences
Given a string S and a string T, count the number of distinct subsequences
of T in S.
A subsequence of a string is a new string which is formed from the original
string by deleting some (can be none) of the characters without disturbing
the relative positions of the remaining characters. (ie, "ACE" is a
subsequence of "ABCDE" while "AEC" is not).
Here is an example:
S = "rabbbit", T = "rabbit"
Return 3.
S和T究竟什么关系?怎么得出3的?
Given a string S and a string T, count the number of distinct subsequences
of T in S.
A subsequence of a string is a new string which is formed from the original
string by deleting some (can be none) of the characters without disturbing
the relative positions of the remaining characters. (ie, "ACE" is a
subsequence of "ABCDE" while "AEC" is not).
Here is an example:
S = "rabbbit", T = "rabbit"
Return 3.
S和T究竟什么关系?怎么得出3的?