package jjn.carl.dp;
import java.util.Scanner;
/** * @author Jjn * @since 2023/8/26 11:06 */public class LeetCode392 {    public boolean isSubsequence(String s, String t) {        int firstIndex = 0;        int secondIndex = 0;        while (secondIndex < t.length() && firstIndex < s.length()) {            if (t.charAt(secondIndex) == s.charAt(firstIndex)) {                firstIndex++;            }            secondIndex++;        }        return firstIndex >= s.length();    }        public static void main(String[] args) {        Scanner scanner = new Scanner(System.in);        String s = scanner.next();        String t = scanner.next();        boolean isSubsequence = new LeetCode392().isSubsequence(s, t);        System.out.println(isSubsequence);    }}

package jjn.carl.dp;
import jjn.round1.LeetCode171_ExcelSheetColumnNumber;
import java.util.Scanner;
/** * @author Jjn * @since 2023/8/26 11:29 */public class LeetCode115 {    public int numDistinct(String s, String t) {        int[][] dp = new int[s.length() + 1][t.length() + 1];        for (int i = 0; i <= s.length(); i++) {            dp[i][0] = 1;        }                for (int i = 1; i <= s.length(); i++) {            for (int j = 1; j <= t.length(); j++) {                if (s.charAt(i - 1) == t.charAt(j - 1)) {                    dp[i][j] = dp[i - 1][j - 1] + dp[i - 1][j];                }else{                    dp[i][j] = dp[i - 1][j];                }            }        }        return dp[s.length()][t.length()];    }        public static void main(String[] args) {        Scanner scanner = new Scanner(System.in);        String s = scanner.next();        String t = scanner.next();        int distinct = new LeetCode115().numDistinct(s, t);        System.out.println(distinct);    }}