#include <bits/stdc++.h>
using namespace std;
#define int long long
#define fastIO() ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
const int mod = 1E9 + 7;
int _hash(string s) {
int p = 257, mod = 13302843816923LL;
int ans = 0;
for (auto c : s) ans = (ans * p + c) % mod;
return ans;
}
int32_t main() {
int n, k;
cin >> n >> k;
string all[n][k];
int hashes[n][k][3]; /// prefix, suffix, all
for (int i = 0; i < n; ++i) {
for (int j = 0; j < k; ++j) {
cin >> all[i][j];
hashes[i][j][2] = _hash(all[i][j]);
if (!i) continue;
hashes[i][j][0] = _hash(all[i][j].substr(0, i));
hashes[i][j][1] = _hash(all[i][j].substr(1));
}
}
int dp[n][k];
for (int i = 0; i < n; ++i) memset(dp[i], 0x00, sizeof(dp[i]));
for (int j = 0; j < k; ++j) dp[0][j] = 1;
for (int i = 1; i < n; ++i) {
for (int j2 = 0; j2 < k; ++j2) {
for (int j1 = 0; j1 < k; ++j1) {
if (hashes[i][j2][0] == hashes[i-1][j1][2] or hashes[i][j2][1] == hashes[i-1][j1][2]) {
dp[i][j2] += dp[i-1][j1];
}
}
dp[i][j2] %= mod;
}
}
int ans = 0;
for (int j = 0; j < k; ++j) ans += dp[n-1][j];
cout << ans%mod << "\n";
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
256 KB |
Output is correct |
2 |
Correct |
5 ms |
256 KB |
Output is correct |
3 |
Correct |
4 ms |
256 KB |
Output is correct |
4 |
Correct |
5 ms |
384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
15 ms |
1024 KB |
Output is correct |
2 |
Correct |
15 ms |
1024 KB |
Output is correct |
3 |
Correct |
15 ms |
1024 KB |
Output is correct |
4 |
Correct |
15 ms |
1024 KB |
Output is correct |
5 |
Correct |
15 ms |
1024 KB |
Output is correct |
6 |
Correct |
15 ms |
1024 KB |
Output is correct |
7 |
Correct |
15 ms |
1024 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
256 KB |
Output is correct |
2 |
Correct |
5 ms |
256 KB |
Output is correct |
3 |
Correct |
4 ms |
256 KB |
Output is correct |
4 |
Correct |
5 ms |
384 KB |
Output is correct |
5 |
Correct |
15 ms |
1024 KB |
Output is correct |
6 |
Correct |
15 ms |
1024 KB |
Output is correct |
7 |
Correct |
15 ms |
1024 KB |
Output is correct |
8 |
Correct |
15 ms |
1024 KB |
Output is correct |
9 |
Correct |
15 ms |
1024 KB |
Output is correct |
10 |
Correct |
15 ms |
1024 KB |
Output is correct |
11 |
Correct |
15 ms |
1024 KB |
Output is correct |
12 |
Correct |
243 ms |
10488 KB |
Output is correct |
13 |
Correct |
241 ms |
10360 KB |
Output is correct |
14 |
Correct |
255 ms |
10488 KB |
Output is correct |
15 |
Correct |
248 ms |
10488 KB |
Output is correct |
16 |
Correct |
248 ms |
10360 KB |
Output is correct |
17 |
Correct |
266 ms |
10484 KB |
Output is correct |
18 |
Correct |
262 ms |
10360 KB |
Output is correct |
19 |
Correct |
264 ms |
10360 KB |
Output is correct |
20 |
Correct |
259 ms |
10360 KB |
Output is correct |
21 |
Correct |
259 ms |
10360 KB |
Output is correct |
22 |
Correct |
248 ms |
10488 KB |
Output is correct |