Submission #902530

#	Time	Username	Problem	Language	Result	Execution time	Memory
902530		duckindog	Magneti (COCI21_magneti)	C++14	30 / 110	82 ms	604 KiB

Main

// from duckindog wth depression
#include<bits/stdc++.h>

using namespace std;

const int N = 50 + 10,
          L = 1e4 + 110,
          M = 1e9 + 7;
int n, l;
int r[N];
void sub1() {
  vector<long long> d(l + 1), f(l + 1);
  const int x = r[1];
  for (int i = 1; i <= l; ++i) d[i] = (d[i - 1] + n) % M;

  for (int i = 2; i <= n; ++i) {

    fill(f.begin(), f.end(), 0);

    for (int j = x; j <= l; ++j) f[j] = (d[j - x] * (n - i + 1)) % M;

    for (int j = 1; j <= l; ++j) d[j] = (d[j - 1] + f[j]) % M;

  }
  cout << d[l];
}

const int S2 = 2e4 + 10;
int fac[S2], ifac[S2];
int powder(int a, int b) {
  long long ret = 1;
  while (b) {
    if (b & 1) ret = ret * a % M;
    a = 1ll * a * a % M;
    b /= 2;
  }
  return ret;
}
int C(int n, int k) {
  if (k < 0) return 0;
  return 1ll * fac[n] * ifac[k] % M * ifac[n - k] % M;
}
void init() {
  int x = 2e4;
  fac[1] = 1;
  for (int i = 2; i <= x; ++i) fac[i] = 1ll * fac[i - 1] * i % M;
  ifac[x] = powder(fac[x], M - 2);
  for (int i = x; i >= 1; --i) ifac[i - 1] = 1ll * ifac[i] * i % M;
}

void sub2() {
  init();

  vector<int> per;
  for (int i = 1; i <= n; ++i) per.push_back(i);
  int answer = 0;
  do {
    int people = l - n;
    for (int i = 1; i < n; ++i) people -= max(r[per[i]] - 1, r[per[i - 1]] - 1);
    answer = (1ll * answer + C(n + people, people)) % M;

  } while (next_permutation(per.begin(), per.end()));
  cout << answer;

}

int32_t main() {
  cin.tie(0)->sync_with_stdio(0);

  if (fopen("duck.inp", "r")) {
    freopen("duck.inp", "r", stdin);
    freopen("duck.out", "w", stdout);
  }
  cin >> n >> l;
  for(int i = 1; i <= n; ++i) cin >> r[i];
  sort(r + 1, r + n + 1);
  int sub = r[1] == r[n] ? 1 : n <= 10 ? 2 : (n <= 30 && l <= 300) ? 3 : 4;

  if (sub == 1) {
    sub1();
    return 0;
  }

  if (sub == 2) {
    sub2();
    return 0;
  }

}

Compilation message (stderr)

Main.cpp: In function 'int32_t main()':
Main.cpp:71:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |     freopen("duck.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:72:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |     freopen("duck.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 50