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 sis 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?
题目含义：字符串t删减多个字母后，能否得到字符串s？
1 public boolean isSubsequence(String s, String t) { 2 int i=0,j=0; 3 if (s.isEmpty()) return true; 4 while (i<s.length() && j<t.length()) 5 { 6 if (s.charAt(i) == t.charAt(j)){ 7 i++;j++; 8 }else 9 { 10 j++; 11 } 12 } 13 return i==s.length(); 14 }