Submission #421079

#	Time	Username	Problem	Language	Result	Execution time	Memory
421079		Chaska	Anagramistica (COCI21_anagramistica)	C++11	10 / 110	1074 ms	11700 KiB

anagramistica

#include <bits/stdc++.h>
using namespace std;
const int N = 2e3+5,mod = 1e9+7;
typedef long long ll;
int n,k;
string a[N];
set<string> s;
map<string,int> sTOi;
int cnt,res[N];
int cb[N][N],dp[N][N];
int main()
{
    cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
    cin >> n >> k;
    for (int i=0;i<n;i++) 
        cin >> a[i];

    for (int i=0;i<n;i++) 
        sort(a[i].begin(),a[i].end());

    for (int i=0;i<n;i++) s.insert(a[i]);

    for (string u : s) sTOi[u] = ++cnt;


    for (int i=0;i<n;i++) res[sTOi[a[i]]]++;
    for (int i=0;i<=n;i++) cerr << res[i] << "\n";

    cb[0][0] = 1;
    for (int i=1;i<=n;i++)  for (int j=0;j<=i;j++) {
        if (j==0) cb[i][j] = 1;
        else {
            cb[i][j] = cb[i-1][j-1] + cb[i-1][j];
            cb[i][j] %= mod;
        }
    }
    for (int i=0;i<=n;i++) {
        for (int j=0;j<=i;j++) cerr << cb[i][j] << " ";
        cerr << "\n";
    }
    dp[0][0] = 1;
    for (int i=1;i<=n;i++) for (int q=0;q<=k;q++) {
        for (int j=0;j<=res[i];j++) {
            ll x = j*(j-1);
            x/= 2;
            ll y;
            y = cb[res[i]][j];
            y %= mod;
           
            if (q>=x) {
                dp[i][q] = dp[i][q] + y*dp[i-1][q-x];
                dp[i][q] %= mod;
            }
        }
        cerr << i << " " << q << " "<<dp[i][q] << "\n";
    }
    cout << dp[n][k];
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 30
• Subtask 3: 0 / 70