leetcode

0 class Solution {

1 static int dp[1001][1001];

2

3 static int rec(const string &s, const string &t, int check, int goal) {

4 if (goal == size(t)) return 1;

5 if (check == size(s)) return 0;

6 if (dp[check][goal] != -1) return dp[check][goal];

7

8 int res = rec(s, t, check + 1, goal);

9 if (s[check] == t[goal]) res += rec(s, t, check + 1, goal + 1);

10 return dp[check][goal] = res;

11 }

12

13 public:

14 int numDistinct(const string &s, const string &t) const {

15 memset(dp, 0xFF, sizeof(dp));

16 return rec(s, t, 0, 0);

17 }

18 };

19

20 int Solution::dp[1001][1001];