//Ye Rooz Khoob Miad ???
#include<bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define all(x) x.begin(), x.end()
#define sz(x) (int) (x).size
using namespace std;
typedef long long ll;
const int N = 2e3 + 10;
const int Inf = 1'061'109'567;
const int Mod = 1e9 + 7;
int power(int a, int b) {
if(b == 0)
return 1;
int res = power(a, b / 2);
res = 1LL * res * res % Mod;
if(b & 1)
res = 1LL * res * a % Mod;
return res;
}
int fac[N + 10], revfac[N + 10];
int C(int n, int r) {
return 1LL * fac[n] * revfac[r] % Mod * revfac[n - r] % Mod;
}
void pre() {
fac[0] = 1;
for(int i = 1; i < N; i++)
fac[i] = 1LL * fac[i - 1] * i % Mod;
revfac[N - 1] = power(fac[N - 1], Mod - 2);
for(int i = N - 2; i >= 0; i--)
revfac[i] = 1LL * (i + 1) * revfac[i + 1] % Mod;
}
int n, k, dp[N][N];
int main(){
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
pre();
cin >> n >> k;
map<string, int> MP;
for(int i = 0; i < n; i++) {
string str;
cin >> str;
sort(all(str));
MP[str]++;
}
int i = 0;
dp[0][0] = 1;
for(auto x : MP) { i++;
for(int j = 0; j <= k; j++) {
for(int l = 0; l <= x.S; l++) {
if(l < C(l, 2)) continue;
dp[i][j] = (dp[i][j] + (dp[i - 1][j - C(l, 2)] * C(x.S, l)) % Mod) % Mod;
}
}
}
cout << dp[i][k];
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
388 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
468 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
388 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
0 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |