再见

#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int mod = 1000000007;

ll dp[201][201];
ll s[201][201];
int main() {
dp[0][0] = 1ll;
int n, m, k;
string a,b;
cin >> n >> m >> k >> a >> b;

for (int i = 1; i <= n; i++) {
    for (int j = m; j >= 1; j--) {
        for (int l = k; l >= 1; l--) {
            if (a[i - 1] == b[j - 1]) 
            {
                s[j][l] = s[j - 1][l] + dp[j - 1][l - 1];
            } 
            else 
            {
                s[j][l] = 0;
            }

            dp[j][l] = (dp[j][l] + s[j][l]) % mod;

        }
    }
}

cout << dp[m][k];

return 0;

}