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You are given two strings?s?and?t?consisting of only lowercase English letters.

Return?the minimum number of characters that need to be appended to the end of?s?so that?t?becomes a?subsequence?of?s.

A?subsequence?is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.

?

Example 1:

Input: s = "coaching", t = "coding"Output: 4Explanation: Append the characters "ding" to the end of s so that s = "coachingding". Now, t is a subsequence of s ("coachingding"). It can be shown that appending any 3 characters to the end of s will never make t a subsequence.

Example 2:

Input: s = "abcde", t = "a"Output: 0Explanation: t is already a subsequence of s ("abcde").

Example 3:

Input: s = "z", t = "abcde"Output: 5Explanation: Append the characters "abcde" to the end of s so that s = "zabcde". Now, t is a subsequence of s ("zabcde"). It can be shown that appending any 4 characters to the end of s will never make t a subsequence.

感覺(jué)這道題可以判斷為easy的，其實(shí)就是判斷一下，按照字符串的順序，相同的一共有多少個(gè)字符，判斷出來(lái)后，剩下就是字符串長(zhǎng)度減去相同的字符數(shù)量即可；

Runtime:?5 ms, faster than?80.00%?of?Java?online submissions for?Append Characters to String to Make Subsequence.

Memory Usage:?43.3 MB, less than?80.00%?of?Java?online submissions for?Append Characters to String to Make Subsequence.