Determine If Two Strings Are Close

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Given two strings s and t, return true if s is a subsequence of t, or false otherwise.
给定两个字符串 s 和 t ，返回 true if s 是的 t 子序列，否则 false 。

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).
字符串的子序列是通过删除某些（可以是无）字符而不干扰其余字符的相对位置而从原始字符串形成的新字符串。（即， "ace" 是 while "aec" 的 "abcde" 子序列不是）。

Example 1: 示例 1：

Input: s = "abc", t = "ahbgdc" Output: true

Example 2: 示例 2：

Input: s = "axc", t = "ahbgdc" Output: false

Constraints: 约束：

0 <= s.length <= 100
0 <= t.length <= 104
s and t consist only of lowercase English letters.
s 并且 t 仅由小写英文字母组成。

Follow up: 跟进： 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?
假设有很多传入 s 的，比如 s1, s2, ..., sk 说在哪里 k >= 109 ，你想一个接一个地检查是否有 t 它的子序列。在这种情况下，您将如何更改代码？

package org.leetcode;  
  
public class IsSubsequence {  
    public boolean isSubsequence(String s, String t) {  
        boolean isSubsequence = false;  
  
        if (s.length() > t.length()) {  
            return isSubsequence;  
        }  
        if (s.length() == 0) {  
            return true;  
        }  
        int sIndex = 0;  
        int tIndex = 0;  
  
        while (tIndex < t.length()) {  
            if (s.charAt(sIndex) == t.charAt(tIndex)) {  
                sIndex++;  
                if (sIndex == s.length()) {  
                    isSubsequence = true;  
                    break;                }  
            }  
            tIndex++;  
        }  
  
  
  
        return isSubsequence;  
    }  
  
    public static void main(String[] args) {  
        IsSubsequence obj = new IsSubsequence();  
        String s1 = "abc";  
        String t1 = "ahbgdc";  
        boolean expect1 = obj.isSubsequence(s1, t1);  
        boolean result1 = true;  
        if (expect1 == result1) {  
            System.out.println("test 1 Pass");  
        } else {  
            System.out.println("Fail expected: " + expect1 + " but got: " + result1);  
        }  
  
        String s2 = "axc";  
        String t2 = "ahbgdc";  
        boolean expect2 = obj.isSubsequence(s2, t2);  
        boolean result2 = false;  
        if (expect2 == result2) {  
            System.out.println("test 2 Pass");  
        } else {  
            System.out.println("Fail expected: " + expect2 + " but got: " + result2);  
        }  
    }  
}