Comment on page

# 392. Is Subsequence

Easy
Given two strings `s` and `t`, return `true` if `s` is a subsequence of `t`, or `false` otherwise.
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).
Example 1:
Input: s = "abc", t = "ahbgdc"
Output:
true
Example 2:
Input: s = "axc", t = "ahbgdc"
Output:
false
Constraints:
• `0 <= s.length <= 100`
• `0 <= t.length <= 104`
• `s` and `t` consist only of lowercase English letters.
Follow up: Suppose there are lots of incoming `s`, say `s1, s2, ..., sk` where `k >= 109`, and you want to check one by one to see if `t` has its subsequence. In this scenario, how would you change your code?

### 解題

Runtime: 0 ms, faster than 100.00%
Memory Usage: 1.9 MB, less than 80.92%
func isSubsequence(s string, t string) bool {
if len(s)==0 { return true }
for i := 0; i < len(t); i++ {
if t[i] == s[0] { s = s[1:] }
if len(s)==0 { return true }
}
return false
}