/*
PROG: source
LANG: C++11
_____
.' '.
/ 0 0 \
| ^ |
| \ / |
\ '---' /
'._____.'
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
struct chash
{
int operator()(int x) const
{
x ^= (x >> 20) ^ (x >> 12);
return x ^ (x >> 7) ^ (x >> 4);
}
int operator()(long long x) const
{
return x ^ (x >> 32);
}
};
template<typename T> using orderedset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T> using hashtable = gp_hash_table<T, T, chash>;
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);
}
template<class T>
T normalize(T x, T mod = 1000000007)
{
return (((x % mod) + mod) % mod);
}
long long randomizell(long long mod)
{
return ((1ll << 45) * rand() + (1ll << 30) * rand() + (1ll << 15) * rand() + rand()) % mod;
}
int randomize(int mod)
{
return ((1ll << 15) * rand() + rand()) % mod;
}
#define y0 ___y0
#define y1 ___y1
#define MP make_pair
#define MT make_tuple
#define PB push_back
#define PF push_front
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define debug(x) cerr << #x << " = " << x << endl;
const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-10;
#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
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pdd;
int H, W;
ll dp[MAXN][MAXN];
bool seen[MAXN][MAXN];
ll ans;
ll solve(ll a, ll b)
{
if (a < 0 || b < 0)
{
return 0;
}
if (a == 0 || b == 0)
{
return 1;
}
if (seen[a][b])
{
return dp[a][b];
}
seen[a][b] = true;
//CONSIDER TOP ROW: place a NS, place an EW, place a N (NO MATCH), a S, a E, a W, a nothing
dp[a][b] += (b) * (a - 1) * solve(a - 2, b - 1);
dp[a][b] += (b) * (b - 1) / 2 * solve(a - 1, b - 2);
dp[a][b] += 4ll * b * solve(a - 1, b - 1);
dp[a][b] += solve(a - 1, b);
dp[a][b] %= INF;
return dp[a][b];
}
int32_t main()
{
ios_base::sync_with_stdio(0);
srand(time(0));
// cout << fixed << setprecision(10);
// cerr << fixed << setprecision(10);
if (fopen("input.in", "r"))
{
freopen ("input.in", "r", stdin);
freopen ("output.out", "w", stdout);
}
cin >> H >> W;
ans = solve(H, W);
ans += (INF - 1);
ans %= INF;
cout << ans << '\n';
//i by W grid, where x of them can only have S and everything else is free
// cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
return 0;
}
Compilation message
tents.cpp: In function 'int32_t main()':
tents.cpp:180:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen ("input.in", "r", stdin);
~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
tents.cpp:181:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
freopen ("output.out", "w", stdout);
~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
376 KB |
Output is correct |
2 |
Correct |
4 ms |
500 KB |
Output is correct |
3 |
Correct |
3 ms |
816 KB |
Output is correct |
4 |
Correct |
4 ms |
1944 KB |
Output is correct |
5 |
Correct |
3 ms |
1944 KB |
Output is correct |
6 |
Correct |
5 ms |
2240 KB |
Output is correct |
7 |
Correct |
4 ms |
2240 KB |
Output is correct |
8 |
Correct |
6 ms |
2376 KB |
Output is correct |
9 |
Correct |
4 ms |
2376 KB |
Output is correct |
10 |
Correct |
7 ms |
2940 KB |
Output is correct |
11 |
Correct |
4 ms |
2940 KB |
Output is correct |
12 |
Correct |
7 ms |
3204 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
376 KB |
Output is correct |
2 |
Correct |
4 ms |
500 KB |
Output is correct |
3 |
Correct |
3 ms |
816 KB |
Output is correct |
4 |
Correct |
4 ms |
1944 KB |
Output is correct |
5 |
Correct |
3 ms |
1944 KB |
Output is correct |
6 |
Correct |
5 ms |
2240 KB |
Output is correct |
7 |
Correct |
4 ms |
2240 KB |
Output is correct |
8 |
Correct |
6 ms |
2376 KB |
Output is correct |
9 |
Correct |
4 ms |
2376 KB |
Output is correct |
10 |
Correct |
7 ms |
2940 KB |
Output is correct |
11 |
Correct |
4 ms |
2940 KB |
Output is correct |
12 |
Correct |
7 ms |
3204 KB |
Output is correct |
13 |
Correct |
3 ms |
3204 KB |
Output is correct |
14 |
Correct |
22 ms |
16784 KB |
Output is correct |
15 |
Correct |
345 ms |
55792 KB |
Output is correct |
16 |
Correct |
7 ms |
55792 KB |
Output is correct |
17 |
Correct |
27 ms |
55792 KB |
Output is correct |
18 |
Correct |
63 ms |
55792 KB |
Output is correct |
19 |
Correct |
290 ms |
62316 KB |
Output is correct |
20 |
Correct |
244 ms |
62316 KB |
Output is correct |
21 |
Correct |
167 ms |
62316 KB |
Output is correct |
22 |
Correct |
157 ms |
62316 KB |
Output is correct |
23 |
Correct |
143 ms |
62316 KB |
Output is correct |
24 |
Correct |
458 ms |
68160 KB |
Output is correct |
25 |
Correct |
332 ms |
68160 KB |
Output is correct |
26 |
Correct |
379 ms |
68160 KB |
Output is correct |
27 |
Correct |
361 ms |
68160 KB |
Output is correct |