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
andt
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?SOLUTION:
class Solution:
def isSubsequence(self, s: str, t: str) -> bool:
i = 0
j = 0
while i < len(s) and j < len(t):
if s[i] == t[j]:
i += 1
j += 1
else:
j += 1
return i == len(s)
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