java代码写子串问题

请注意，下面的代码仅为问题的一种实现方式，可能需要根据具体情况进行修改。

import java.util.*;
public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int k = sc.nextInt();
        String s = sc.next();
        String t = sc.next();
        int[][] dp = new int[n+1][k+1];
        dp[0][0] = 1;
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= k; j++) {
                dp[i][j] = dp[i-1][j]; // 不选 s[i]
                int match = 0;
                for (int p = i-1; p >= 0 && i-p <= m; p--) {
                    match = match * 26 + (s.charAt(p) - 'a');
                    if (i-p >= match && match > 0 && match <= m && t.startsWith(s.substring(p, i))) {
                        dp[i][j] = (dp[i][j] + dp[p][j-1]) % MOD; // 选 s[p+1...i]
                    }
                }
            }
        }
        System.out.println(dp[n][k]);
    }
}