Submission #200982

#	Time	Username	Problem	Language	Result	Execution time	Memory
200982		model_code	Zapina (COCI20_zapina)	C++17	110 / 110	356 ms	3448 KiB

zapina

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef double lf;
typedef long double Lf;
typedef pair <int,int> pii;
typedef pair <ll, ll> pll;

#define TRACE(x) cerr << #x << "  " << x << endl
#define FOR(i, a, b) for (int i = (a); i < int(b); i++)
#define REP(i, n) FOR(i, 0, n)
#define all(x) (x).begin(), (x).end()
#define _ << " " <<

#define fi first
#define sec second
#define mp make_pair
#define pb push_back

const int MAXN = 501;
const int MOD = 1e9 + 7;

int add(int a, int b) {
  a += b;
  if (a >= MOD) a -= MOD;
  return a;
}

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

int n, dp[2][MAXN][MAXN];
int povrh[MAXN][MAXN];

int rek(int ok, int a, int b) {
  if (b == n + 1) {
    if (a != 0) return 0;
    return ok;
  }
  if (a == 0) return ok;
  if (dp[ok][a][b] != -1) return dp[ok][a][b];
  int ret = 0;
  REP(i, a + 1) {
    ret = add(ret, mul(povrh[a][i], rek(ok | (b == i), a - i, b + 1)));
  }
  return dp[ok][a][b] = ret;
}

int main() {
  cin >> n;
  memset(dp, -1, sizeof dp);
  povrh[0][0] = 1;
  FOR(i, 1, MAXN) {
    REP(j, i + 1) {
      povrh[i][j] = povrh[i - 1][j];
      if (j) povrh[i][j] = add(povrh[i][j], povrh[i - 1][j - 1]);
    }
  }
  cout << rek(0, n, 1) << endl;
  return 0;
}

• Subtask 1: 22 / 22
• Subtask 2: 33 / 33
• Subtask 3: 55 / 55