#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ar array
const int MOD=1e9+7, P=37;
int getHash(string s) {
ll pp=1, hsh=0;
for (char c : s) {
hsh=(hsh+(c-'a'+1)*pp)%MOD;
pp=pp*P%MOD;
}
return hsh;
}
int n, k;
string name[50][1500];
unordered_map<int, int> dp, last;
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> k;
for (int i=0; i<n; ++i) for (int j=0; j<k; ++j) cin >> name[i][j];
for (int i=0; i<k; ++i) dp[getHash(name[0][i])]=1;
for (int i=1; i<n; ++i) { //current string is of length i+1
swap(dp, last);
dp.clear();
for (int j=0; j<k; ++j) {
int cur=getHash(name[i][j]);
int hsh=getHash(name[i][j].substr(0, i));
auto it=last.find(hsh);
if (it!=last.end()) dp[cur]+=it->second;
int hsh2=getHash(name[i][j].substr(1));
if (hsh!=hsh2) {
hsh=hsh2;
it=last.find(hsh);
if (it!=last.end()) dp[cur]+=it->second;
}
}
//for (auto& x : dp) {cout << x.first << " " << x.second << "\n";}
for (auto& x : dp) if (x.second>=MOD) x.second-=MOD;
//cout << "\n\n";
}
int ans=0;
for (auto& x : dp) ans=(ans+x.second)%MOD;
cout << ans << "\n";
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
2688 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
2688 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
8 ms |
2944 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
2688 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
2688 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
