判断是否为子序列

public class Demo1 {

public static void main(String[] args) {
    String    s = "abp";
    String  t = "ahbgdc";
    System.out.println(isSubsequence(s,t));        
}
public static boolean isSubsequence(String s, String t) {
    int index = -1;
    for (char c : s.toCharArray()) {
        index = t.indexOf(c,index+1);
        System.out.println(index);        
        if (index == -1) {
            return false;
        }
    }
    return true;
}

}