Submission #512733

#	Time	Username	Problem	Language	Result	Execution time	Memory
512733		blue	Anagramistica (COCI21_anagramistica)	C++17	110 / 110	15 ms	16712 KiB

anagramistica

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

using vi = vector<int>;
using vvi = vector<vi>;
using ll = long long;

const ll mod = 1'000'000'007;

int ad(ll a, ll b)
{
    return (a+b)%mod;
}

int mul(ll a, ll b)
{
    return (a*b)%mod;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n, k;
    cin >> n >> k;

    string s[n];
    vi val{0};
    for(int i = 0; i < n; i++)
    {
        cin >> s[i];
        sort(s[i].begin(), s[i].end());
    }
    sort(s, s+n);


    for(int i = 0; i < n; i++)
    {
        if(i == 0 || s[i] != s[i-1]) val.push_back(1);
        else val.back()++;
    }



    int ch[1+n][1+n];
    for(int i = 0; i <= n; i++)
    {
        ch[i][0] = ch[i][i] = 1;
        for(int j = 1; j < i; j++)
            ch[i][j] = (ch[i-1][j] + ch[i-1][j-1]) % mod;
    }

    int z = int(val.size())-1;

    vvi dp(1+z, vi(1+k, 0));
    dp[0][0] = 1;

    for(int i = 1; i <= z; i++)
    {
        for(int j = 0; j <= k; j++)
        {
            for(int c = 0; j - (c*(c-1)/2) >= 0 && c <= val[i]; c++)
            {
                dp[i][j] = ad(dp[i][j], mul(ch[val[i]][c], dp[i-1][j - (c*(c-1))/2]));
            }
        }
    }

    cout << dp[z][k] << '\n';
}

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