#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 2e3+4;
const int mod = 1e9+7;
map<string,int> cnt,dp;
int n,k,ans;
int P(int a,int b){ return 1ll*a*b%mod;}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> k;
for (int i=1; i<=n; i++) for (int j=0; j<k; j++){
string s,t1,t2; cin >> s;
if (i == 1) dp[s] = 1;
else if (!dp.count(s)){ t1 = s.substr(0, i-1), t2 = s.substr(1, i-1);
if (dp.count(t1)) dp[s] = (dp[s] + P(dp[t1], cnt[t1]))%mod;
if (t1 != t2 && dp.count(t2)) dp[s] = (dp[s] + P(dp[t2], cnt[t2]))%mod;
}
cnt[s]++;
if (i == n) ans = (ans + dp[s])%mod;
}
cout << ans << "\n";
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
10 ms |
1364 KB |
Output is correct |
2 |
Correct |
10 ms |
1480 KB |
Output is correct |
3 |
Correct |
11 ms |
1492 KB |
Output is correct |
4 |
Correct |
2 ms |
340 KB |
Output is correct |
5 |
Correct |
10 ms |
1236 KB |
Output is correct |
6 |
Correct |
9 ms |
1236 KB |
Output is correct |
7 |
Correct |
2 ms |
464 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
10 ms |
1364 KB |
Output is correct |
6 |
Correct |
10 ms |
1480 KB |
Output is correct |
7 |
Correct |
11 ms |
1492 KB |
Output is correct |
8 |
Correct |
2 ms |
340 KB |
Output is correct |
9 |
Correct |
10 ms |
1236 KB |
Output is correct |
10 |
Correct |
9 ms |
1236 KB |
Output is correct |
11 |
Correct |
2 ms |
464 KB |
Output is correct |
12 |
Correct |
240 ms |
18436 KB |
Output is correct |
13 |
Correct |
220 ms |
18280 KB |
Output is correct |
14 |
Correct |
215 ms |
18064 KB |
Output is correct |
15 |
Correct |
231 ms |
18124 KB |
Output is correct |
16 |
Correct |
16 ms |
2216 KB |
Output is correct |
17 |
Correct |
178 ms |
14064 KB |
Output is correct |
18 |
Correct |
189 ms |
14212 KB |
Output is correct |
19 |
Correct |
188 ms |
14128 KB |
Output is correct |
20 |
Correct |
185 ms |
14140 KB |
Output is correct |
21 |
Correct |
183 ms |
14452 KB |
Output is correct |
22 |
Correct |
17 ms |
2224 KB |
Output is correct |