蓝桥杯（3.18 刷真题）
P8697 [蓝桥杯 2019 国 C] 最长子序列
AC
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String s1 = sc.nextLine();
String s2 = sc.nextLine();
char[] c1 = s1.toCharArray();
char[] c2 = s2.toCharArray();
int ans = 0;
for(int i=0,j=0;i<c1.length&&j<c2.length;i++) {
if(c1[i] == c2[j]) {
j++;
ans++;
}
}
System.out.println(ans);
}
}