Given a string s and a string t, check if s is subsequence of t.
You may assume that there is only lower case English letters in both s and t. t is potentially a very long (length ~= 500,000) string, and s is a short string (<=100).
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).
Example 1:
s = "abc", t = "ahbgdc"
Return true.
Example 2:
s = "axc", t = "ahbgdc"
Return false.
Follow up:
If there are lots of incoming S, say S1, S2, ... , Sk where k >= 1B, and you want to check
one by one to see if T has its subsequence. In this scenario, how would you change your
code?
Credits:
Special thanks to @pbrother
for adding this problem and creating all test cases.