Submission #48811

#	Time	Username	Problem	Language	Result	Execution time	Memory
48811		qkxwsm	Tents (JOI18_tents)	C++17	48 / 100	2066 ms	81236 KiB

tents

/*
PROG: joi_tents
LANG: C++11
    _____
  .'     '.
 /  0   0  \
|     ^     |
|  \     /  |
 \  '---'  /
  '._____.'
 */
#include <bits/stdc++.h>

using namespace std;

template<class T>
void readi(T &x)
{
	T input = 0;
	bool negative = false;
	char c = ' ';
	while (c < '-')
	{
		c = getchar();
	}
	if (c == '-')
	{
		negative = true;
		c = getchar();
	}
	while (c >= '0')
	{
		input = input * 10 + (c - '0');
		c = getchar();
	}
	if (negative)
	{
		input = -input;
	}
	x = input;
}
template<class T>
void printi(T output)
{
	if (output == 0)
	{
		putchar('0');
		return;
	}
	if (output < 0)
	{
		putchar('-');
		output = -output;
	}
	int aout[20];
	int ilen = 0;
	while(output)
	{
		aout[ilen] = ((output % 10));
		output /= 10;
		ilen++;
	}
	for (int i = ilen - 1; i >= 0; i--)
	{
		putchar(aout[i] + '0');
	}
	return;
}
template<class T>
void ckmin(T &a, T b)
{
	a = min(a, b);
}
template<class T>
void ckmax(T &a, T b)
{
	a = max(a, b);
}
long long randomize(long long mod)
{
	return ((1ll << 30) * rand() + (1ll << 15) * rand() + rand()) % mod;
}

#define MP make_pair
#define PB push_back
#define PF push_front
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second

const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-20;

#define MAGIC 347
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll
#define MAXN 3013

long long normalize(long long x, long long mod = INF)
{
	return (((x % mod) + mod) % mod);
}

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

int N, M;
ll dp[2][MAXN][MAXN];
ll ans;

ll choose2(ll x)
{
	return (x * (x - 1) / 2) % INF;
}
void mark(int x, int y, ll val)
{
	if (x < 0 || x > M || y < 0 || y > M)
	{
		return;
	}
	dp[1][x][y] += val;
	dp[1][x][y] %= INF;
	return;
}
int32_t main()
{
	ios_base::sync_with_stdio(0); 
	srand(time(0));
	//	cout << fixed << setprecision(12);	
	//	cerr << fixed << setprecision(12);
	if (fopen("joi_tents.in", "r"))
	{	
		freopen ("joi_tents.in", "r", stdin);
		freopen ("joi_tents.out", "w", stdout);
	}
	cin >> N >> M;
	if (N < M)
	{
		swap(N, M);
	}
	//# blank, #N-only
	dp[0][M][0] = 1;
	for (int i = 0; i < N; i++)
	{
		//add nothing
		//add only one N
		//add only one S to an N
		//add only one S
		//add only one E
		//add only one W
		//add EW
		for (int j = 0; j <= M; j++)
		{
			for (int k = 0; k <= M; k++)
			{
				ll val = dp[0][j][k];
				mark(j, k, val);
				mark(j - 1, k + 1, val * j);
				mark(j, k - 1, val * k);
				mark(j - 1, k, 3ll * val * j);
				mark(j - 2, k, val * choose2(j));
			}
		}
		for (int j = 0; j <= M; j++)
		{
			for (int k = 0; k <= M; k++)
			{
				dp[0][j][k] = dp[1][j][k];
				dp[1][j][k] = 0;
			}
		}
	}
	ans += (INF - 1);
	for (int i = 0; i <= M; i++)
	{
		for (int j = 0; j <= M; j++)
		{
			ans += dp[0][i][j];
			ans %= INF;
		}
	}
	cout << ans << '\n';
	//	cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
	return 0;
}

Compilation message (stderr)

tents.cpp: In function 'int32_t main()':
tents.cpp:141:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen ("joi_tents.in", "r", stdin);
   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
tents.cpp:142:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen ("joi_tents.out", "w", stdout);
   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 48 / 48
• Subtask 2: 0 / 52