// "Say:He is the Most Merciful,We have believed in him and upon him we have relied" [67:29]
//#pragma GCC optimize ("Ofast")
//#pragma GCC target ("avx2")
//#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
using namespace std;
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
*/
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<ll> vll;
typedef vector<int> vii;
typedef map<int,int> mpi;
typedef map<ll,ll> mpl;
typedef unordered_map<int,int> umpi;
typedef unordered_map<ll,ll> umpl;
#define ump unordered_map
#define mod 1000000007
#define inf 1000000000000000006
#define infi 1000000009
#define ff first
#define ss second
#define pb push_back
#define all(v) v.begin(), v.end()
#define fastio ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define endl '\n'
#define pi acos(-1.0)
#define dec(n) fixed << setprecision(n)
#define N 200005
//#define int long long
struct ss{
ll hash[55];
};
ll bigmod(ll a,ll b){
if(b==0) return 1;
ll ret=bigmod(a,b/2);
ret*=ret;
ret%=mod;
if(b%2==1) ret*=a;
return ret%mod;
}
vector<ss> v[55];
string s;
int n,k;
ll dp[1505][55],inv;
ll DP(int p,int x){
if(x==n) return 1;
if(dp[p][x]!=-1) return dp[p][x];
ll ret=0;
for(int i=0;i<k;i++){
if(v[x][i].hash[x]==v[x-1][p].hash[x] || ((((v[x][i].hash[x+1]-v[x][i].hash[1])*inv)+mod)%mod)==v[x-1][p].hash[x]) ret+=DP(i,x+1);
ret%=mod;
}
return dp[p][x]=ret;
}
void solve(){
cin >> n >> k;
for(int i=0;i<n;i++){
v[i].resize(k);
for(int j=0;j<k;j++){
cin >> s;
ss tmp;
ll p=31,hashval=0,pw=1;
for(int k=0;k<s.size();k++){
hashval=(hashval+(s[k]-'a'+1)*pw)%mod;
pw=(pw*p)%mod;
tmp.hash[k+1]=hashval;
}
v[i][j]=tmp;
}
}
inv=bigmod(31,mod-2);
memset(dp,-1,sizeof dp);
ll ans=0;
for(int i=0;i<k;i++){
ans+=DP(i,1);
ans%=mod;
}
cout << ans << endl;
}
signed main(){
fastio;
//srand(chrono::steady_clock::now().time_since_epoch().count());
int T=1,cs=0;
//cin >> T;
while(T--){
//cout << "Case " << ++cs << ":" << " " ;
solve();
}
}
Compilation message
trener.cpp: In function 'void solve()':
trener.cpp:81:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
81 | for(int k=0;k<s.size();k++){
| ~^~~~~~~~~
trener.cpp: In function 'int main()':
trener.cpp:103:13: warning: unused variable 'cs' [-Wunused-variable]
103 | int T=1,cs=0;
| ^~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
972 KB |
Output is correct |
2 |
Correct |
1 ms |
956 KB |
Output is correct |
3 |
Correct |
1 ms |
972 KB |
Output is correct |
4 |
Correct |
1 ms |
972 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
3148 KB |
Output is correct |
2 |
Correct |
8 ms |
3148 KB |
Output is correct |
3 |
Correct |
7 ms |
3148 KB |
Output is correct |
4 |
Correct |
14 ms |
3244 KB |
Output is correct |
5 |
Correct |
7 ms |
3148 KB |
Output is correct |
6 |
Correct |
9 ms |
3148 KB |
Output is correct |
7 |
Correct |
8 ms |
3236 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
972 KB |
Output is correct |
2 |
Correct |
1 ms |
956 KB |
Output is correct |
3 |
Correct |
1 ms |
972 KB |
Output is correct |
4 |
Correct |
1 ms |
972 KB |
Output is correct |
5 |
Correct |
6 ms |
3148 KB |
Output is correct |
6 |
Correct |
8 ms |
3148 KB |
Output is correct |
7 |
Correct |
7 ms |
3148 KB |
Output is correct |
8 |
Correct |
14 ms |
3244 KB |
Output is correct |
9 |
Correct |
7 ms |
3148 KB |
Output is correct |
10 |
Correct |
9 ms |
3148 KB |
Output is correct |
11 |
Correct |
8 ms |
3236 KB |
Output is correct |
12 |
Correct |
1302 ms |
33708 KB |
Output is correct |
13 |
Correct |
1143 ms |
34060 KB |
Output is correct |
14 |
Correct |
1155 ms |
34060 KB |
Output is correct |
15 |
Correct |
1196 ms |
34116 KB |
Output is correct |
16 |
Correct |
861 ms |
34180 KB |
Output is correct |
17 |
Correct |
1215 ms |
34116 KB |
Output is correct |
18 |
Correct |
1087 ms |
34120 KB |
Output is correct |
19 |
Correct |
1078 ms |
33992 KB |
Output is correct |
20 |
Correct |
1096 ms |
34116 KB |
Output is correct |
21 |
Correct |
1108 ms |
34112 KB |
Output is correct |
22 |
Correct |
859 ms |
34116 KB |
Output is correct |