Submission #641092

#	Time	Username	Problem	Language	Result	Execution time	Memory
641092		ghostwriter	Tents (JOI18_tents)	C++14	100 / 100	123 ms	63236 KiB

tents

#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.h>
#endif
#define st first
#define nd second
#define pb push_back
#define pf push_front
#define _pb pop_back
#define _pf pop_front
#define lb lower_bound
#define ub upper_bound
#define mtp make_tuple
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
typedef long long ll; typedef unsigned long long ull;
typedef double db; typedef long double ldb;
typedef pair<int, int> pi; typedef pair<ll, ll> pll;
typedef vector<int> vi; typedef vector<ll> vll; typedef vector<pi> vpi; typedef vector<pll> vpll;
typedef string str;
template<typename T> T gcd(T a, T b) { return (b == 0? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
#define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
#define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
#define EACH(i, x) for (auto &(i) : (x))
#define WHILE while
#define file "TEST"
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }
/*
    Tran The Bao
    CTL - Da Lat
    Cay ngay cay dem nhung deo duoc cong nhan
*/
const int M = 1e9 + 7;
const int N = 3005;
int h, w, c[N][N], d[N][N], f[N], pi2[N], rs = 0;
signed main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);
    cin >> h >> w;
    FOR(i, 0, h)
    FOR(j, 0, w)
    	if (i == 0 || j == 0) d[i][j] = 1;
    	else d[i][j] = (d[i][j - 1] + 4LL * i * d[i - 1][j - 1] % M) % M;
    FOR(i, 0, max(h, w))
    FOR(j, 0, i)
    	if (j == 0) c[i][j] = 1;
    	else c[i][j] = (c[i - 1][j] + c[i - 1][j - 1]) % M;
    f[0] = pi2[0] = 1;
    int inv2 = (-M / 2 + M) % M;
    FOR(i, 1, max(h, w)) {
    	f[i] = 1LL * f[i - 1] * i % M;
    	pi2[i] = 1LL * pi2[i - 1] * inv2 % M;
    }
    FOR(i, 0, min(h, w / 2)) {
		int tmp1 = 1LL * c[h][i] * c[w][2 * i] % M * f[2 * i] % M *pi2[i] % M;
    	int rmx = h - i, rmy = w - 2 * i;
    	FOR(j, 0, min(rmy, rmx / 2)) {
    		int tmp2 = 1LL * c[rmy][j] * c[rmx][2 * j] % M * f[2 * j] % M * pi2[j] % M;
    		int tmp3 = d[rmx - 2 * j][rmy - j];
    		rs = (rs + 1LL * tmp1 * tmp2 % M * tmp3 % M) % M;
    	}
    }
    cout << (rs - 1) % M;
    return 0;
}

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:24:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
tents.cpp:44:5: note: in expansion of macro 'FOR'
   44 |     FOR(i, 0, h)
      |     ^~~
tents.cpp:24:31: warning: unnecessary parentheses in declaration of 'j' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
tents.cpp:45:5: note: in expansion of macro 'FOR'
   45 |     FOR(j, 0, w)
      |     ^~~
tents.cpp:24:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
tents.cpp:48:5: note: in expansion of macro 'FOR'
   48 |     FOR(i, 0, max(h, w))
      |     ^~~
tents.cpp:24:31: warning: unnecessary parentheses in declaration of 'j' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
tents.cpp:49:5: note: in expansion of macro 'FOR'
   49 |     FOR(j, 0, i)
      |     ^~~
tents.cpp:24:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
tents.cpp:54:5: note: in expansion of macro 'FOR'
   54 |     FOR(i, 1, max(h, w)) {
      |     ^~~
tents.cpp:24:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
tents.cpp:58:5: note: in expansion of macro 'FOR'
   58 |     FOR(i, 0, min(h, w / 2)) {
      |     ^~~
tents.cpp:24:31: warning: unnecessary parentheses in declaration of 'j' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
tents.cpp:61:6: note: in expansion of macro 'FOR'
   61 |      FOR(j, 0, min(rmy, rmx / 2)) {
      |      ^~~

• Subtask 1: 48 / 48
• Subtask 2: 52 / 52