题目:
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 s is 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?
题目描述:
判断s是否为t的子序列
具体解题思路及代码如下:
package Leetcode_Github; public class GreedyThought_IsSubsequence_392_1112 { public boolean IsSubsequence(String s, String t) { //记录s中字符在t中出现的位置 int index = -1; //从头向后遍历字符串t for (char c : s.toCharArray()) { index = t.indexOf(c, index + 1); if (index == -1) { return false; } } return true; } }