#include <bits/stdc++.h>
using namespace std;
#define IOS ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define fort(itr,map) for(auto itr = map.begin(); itr != map.end(); ++itr)
#define pb push_back
#define elif else if
#define F first
#define S second
#define all(v) v.begin(), v.end()
#define uni(v) sort(all(v)), v.erase(unique(all(v)), v.end())
#define err_dp(i, j) cout << "dp[" << i << "][" << j << "] = " << dp[i][j] << endl;
#define int long long
const int MAX = 3e3 + 10;
const int MOD = 1e9 + 7;
int dp[MAX][MAX];
int cu_pow(int a, int b){
if(b == 1) return a;
int ans = cu_pow(a, b / 2);
ans = 1LL * ans * ans; ans = ans % MOD;
if(b % 2) ans = 1LL * ans * a; ans = ans % MOD;
return ans % MOD;
}
int comb(int x){
return 1LL * x * (x - 1) * cu_pow(2, MOD - 2) % MOD;
}
main()
{IOS;
int n, m; cin >> n >> m;
for(int i = 0; i <= n; i++) dp[i][0] = 1;
for(int j = 0; j <= m; j++) dp[0][j] = 1;
for(int i = 1; i <= n; i++){
for(int j = 1; j <= m; j++){
int res = 1LL * 4 * i * (dp[i - 1][j - 1]); res = res % MOD;
res = res + (dp[i][j - 1]); res = res % MOD;
if(i > 1)
res = res + (1LL * comb(i) * dp[i - 2][j - 1]), res = res % MOD;
if(j > 1)
res = res + (1LL * (i * (j - 1))) * dp[i - 1][j - 2], res = res % MOD;
dp[i][j] = res;
}
}
cout << (dp[n][m] - 1 + MOD) % MOD << endl;
}
Compilation message
tents.cpp: In function 'long long int cu_pow(long long int, long long int)':
tents.cpp:24:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
24 | if(b % 2) ans = 1LL * ans * a; ans = ans % MOD;
| ^~
tents.cpp:24:36: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
24 | if(b % 2) ans = 1LL * ans * a; ans = ans % MOD;
| ^~~
tents.cpp: At global scope:
tents.cpp:32:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
32 | main()
| ^~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
600 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
2396 KB |
Output is correct |
4 |
Correct |
1 ms |
6492 KB |
Output is correct |
5 |
Correct |
3 ms |
2396 KB |
Output is correct |
6 |
Correct |
5 ms |
6492 KB |
Output is correct |
7 |
Correct |
4 ms |
2560 KB |
Output is correct |
8 |
Correct |
5 ms |
6492 KB |
Output is correct |
9 |
Correct |
1 ms |
4444 KB |
Output is correct |
10 |
Correct |
9 ms |
8652 KB |
Output is correct |
11 |
Correct |
1 ms |
2396 KB |
Output is correct |
12 |
Correct |
18 ms |
8540 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
600 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
2396 KB |
Output is correct |
4 |
Correct |
1 ms |
6492 KB |
Output is correct |
5 |
Correct |
3 ms |
2396 KB |
Output is correct |
6 |
Correct |
5 ms |
6492 KB |
Output is correct |
7 |
Correct |
4 ms |
2560 KB |
Output is correct |
8 |
Correct |
5 ms |
6492 KB |
Output is correct |
9 |
Correct |
1 ms |
4444 KB |
Output is correct |
10 |
Correct |
9 ms |
8652 KB |
Output is correct |
11 |
Correct |
1 ms |
2396 KB |
Output is correct |
12 |
Correct |
18 ms |
8540 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
14 |
Correct |
9 ms |
55900 KB |
Output is correct |
15 |
Correct |
1045 ms |
66136 KB |
Output is correct |
16 |
Correct |
67 ms |
6724 KB |
Output is correct |
17 |
Correct |
233 ms |
17016 KB |
Output is correct |
18 |
Correct |
287 ms |
29284 KB |
Output is correct |
19 |
Correct |
1202 ms |
70232 KB |
Output is correct |
20 |
Correct |
964 ms |
60116 KB |
Output is correct |
21 |
Correct |
635 ms |
39588 KB |
Output is correct |
22 |
Correct |
629 ms |
51872 KB |
Output is correct |
23 |
Correct |
354 ms |
70408 KB |
Output is correct |
24 |
Correct |
1661 ms |
71032 KB |
Output is correct |
25 |
Correct |
1236 ms |
62184 KB |
Output is correct |
26 |
Correct |
1414 ms |
68340 KB |
Output is correct |
27 |
Correct |
1595 ms |
70392 KB |
Output is correct |