Submission #476604

#	Time	Username	Problem	Language	Result	Execution time	Memory
476604		mychecksedad	Anagramistica (COCI21_anagramistica)	C++17	10 / 110	19 ms	19284 KiB

anagramistica

 #include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define pb push_back
#define all(x) x.begin(), x.end()
ll MOD = 1e9+7;
const int N = 2010, M = 1e5+10, F = 2147483646, K = 20;



int n, k, c[N][N], dp[N][N];
string s[N];
map<string, int> ms;
void precalc(){
    for(int i = 0; i < N; i++) c[i][0] = 1, c[0][i] = 0;
    for(int i = 1; i < N; i++){
        for(int j = 1; j <= i; j++){
            //c(n, k) = c(n - 1, k - 1) + c(n - 1, k)
            if(i==j) c[i][j] = 1;
            else c[i][j] = (c[i - 1][j - 1] + c[i - 1][j])%MOD;
        }
    }
}



int main(){
    cin.tie(0); ios::sync_with_stdio(0);
    cin >> n >> k;
    precalc();
    for(int i = 0; i < n; i++){
        cin >> s[i];
        sort(all(s[i]));
        ++ms[s[i]];
    }
    for(int j = 0; j <= n; j++) for(int i = 0; i <= k; i++) dp[j][i] = 0;
    dp[0][0] = 1;
    int cur = 1;
    ll f = 0;
    for(auto kk: ms){
        ll x = kk.second;
        // for(int i = 0; i <= k; i++) dp[cur][i] = dp[cur-1][i];
        for(int j = 0; j <= x && j * (j - 1) / 2 <= k; j++)
            for(int i = k; i >= 0; --i){
                if(i >= j * (j - 1) / 2){
                    (dp[cur][i] += (dp[cur - 1][i - j * (j - 1) / 2] * c[x][j])) %= MOD;
                    // cout << cur << ' '  << i << ' ' << dp[cur][i] << '\n';
                }
            }
        // cout << kk.first << '\n';
        ++cur;
    }
    cout << dp[cur - 1][k];

    return 0;
}

Compilation message (stderr)

anagramistica.cpp: In function 'int main()':
anagramistica.cpp:39:8: warning: unused variable 'f' [-Wunused-variable]
   39 |     ll f = 0;
      |        ^

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