Submission #1269880

#	Time	Username	Problem	Language	Result	Execution time	Memory
1269880		Bui_Quoc_Cuong	Magneti (COCI21_magneti)	C++20	110 / 110	94 ms	54600 KiB

Main

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

#define mp make_pair
#define mt make_tuple
#define pb push_back
#define sz(v) (int)v.size()
#define fi first
#define se second
#define ALL(A) A.begin(), A.end()
#define compact(v) v.erase(unique(ALL(v)), end(v))

#define FOR(i, a, b) for(int i = (a); i <= (int)(b); i++)
#define FORD(i, a, b) for(int i = (a); i >= (int)(b); i--)
#define BIT(mask,i) ((mask>>(i))&1)
#define MASK(a) (1LL << (a))

#define lwb lower_bound
#define upb upper_bound

#define dbg(x) "[" #x " = " << (x) << "]"
#define file(task) if(fopen(task".inp", "r")){ freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); }

template<typename T>
bool minimize (T& a, const T& b) {
    if (a > b) return a = b, true;
    return false;
}

template<typename T>
bool maximize (T& a, const T& b) {
    if (a < b) return a = b, true;
    return false;
}

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using db = double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

using vi = vector<int>;
using vb = vector<bool>;
using vll = vector<ll>;
using vpi = vector<pii>;
using vpl = vector<pll>;

const int maxn = 105;
const int mod = 1e9 + 7;

int n, L;
int r[maxn];

int fact[20005], inv_fact[20005];

int dp[55][55][10005];

int iPow(int x, int y) {
     if (y == 0) return 1;
     if (y == 1) return x;
     int c = iPow(x, y / 2);
     if (y & 1) return 1LL * c * c % mod * x % mod;
     else return 1LL * c * c % mod;
}

inline int C(int n, int k) {
     return 1LL * fact[n] * inv_fact[n - k] % mod * inv_fact[k] % mod;
}

void add(int &x, const int y) {
     x+= y;
     if (x >= mod) x-= mod;
}

void solve() {
     cin >> n >> L;
     FOR(i, 1, n) cin >> r[i];

     fact[0] = 1;
     FOR(i, 1, 20000) fact[i] = 1LL * fact[i - 1] * i % mod;
     inv_fact[20000] = iPow(fact[20000], mod - 2);
     FORD(i, 19999, 0) inv_fact[i] = 1LL * inv_fact[i + 1] * (i + 1) % mod;

     sort(r + 1, r + 1 + n);
     dp[1][1][1] = 1;

     /// goi dp[i][j][d] : xet tu 1 ... i co j nhom va tong khoang cach la d

     FOR(i, 1, n) FOR(j, 0, i) FOR(d, 1, L) {
          add(dp[i + 1][j + 1][d + 1], 1LL * (j + 1) * dp[i][j][d] % mod);
          if(d + r[i + 1] <= L){
               add(dp[i + 1][j][d + r[i + 1]], 1LL * 2 * j % mod * dp[i][j][d] % mod);
          }
          if(j > 1 && d + 2 * r[i + 1] - 1 <= L){
               add(dp[i + 1][j - 1][d + 2 * r[i + 1] - 1], 1LL * dp[i][j][d] * (j - 1) % mod);
          }
     }

     int ans = 0;
     FOR(i, 1, L) {
          add(ans, 1LL * dp[n][1][i] * C(L - i + n, n) % mod);
     }
     cout << ans;
}

signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    file("kieuoanh");

    int tc = 1; // cin >> tc;
    while (tc--) solve();

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:22:55: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 | #define file(task) if(fopen(task".inp", "r")){ freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); }
      |                                                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:109:5: note: in expansion of macro 'file'
  109 |     file("kieuoanh");
      |     ^~~~
Main.cpp:22:88: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 | #define file(task) if(fopen(task".inp", "r")){ freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); }
      |                                                                                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:109:5: note: in expansion of macro 'file'
  109 |     file("kieuoanh");
      |     ^~~~

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