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.
思路:双指针,用j来循环t,如果找到了s.charAt(i), 那么i++,如果i == s.length(),就证明我找完了。
class Solution {
public boolean isSubsequence(String s, String t) {
if(s.isEmpty()) {
return true;
}
if(s.length() > t.length()) {
return false;
}
int i = 0;
for(int j = 0; j < t.length(); j++) {
if(t.charAt(j) == s.charAt(i)) {
i++;
}
if(i == s.length()) {
return true;
}
}
return i == s.length();
}
}