Given a string s and a string t, check if s is subsequence of t.
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).
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.
Example 1:
Input: s = "abc", t = "ahbgdc" Output: true
Example 2:
Input: s = "axc", t = "ahbgdc" Output: false
Constraints:
0 <= s.length <= 1000 <= t.length <= 10^4- Both strings consists only of lowercase characters.
Related Topics:
Binary Search, Dynamic Programming, Greedy
Similar Questions:
// OJ: https://leetcode.com/problems/is-subsequence/
// Author: github.com/lzl124631x
// Time: O(M + N)
// Space: O(1)
class Solution {
public:
bool isSubsequence(string s, string t) {
int i = 0, j = 0, M = s.size(), N = t.size();
for (; i < M && j < N; ++j) {
if (s[i] == t[j]) ++i;
}
return i == M;
}
};