Submission #56310

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
56310	2018-07-11T04:27:19 Z	김세빈(#1599)	Tents (JOI18_tents)	C++11	100 / 100	441 ms	189348 KB

tents

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const ll mod = 1e9 + 7;

ll H[3030][3030], V[3030][3030];
ll D[3030][3030];
ll n, m, ans;

int main()
{
	ll i, j;
	
	scanf("%lld%lld", &n, &m);
	
	H[0][0] = V[0][0] = 1;
	
	D[0][0] = 1;
	for(i=1;i<=n || i<=m;i++){
		D[i][0] = 1;
		for(j=1;j<=i;j++){
			D[i][j] = (D[i-1][j-1] + D[i-1][j]) % mod;
		}
	}
	
	for(i=1;i<=n;i++){
		for(j=0;j<=m;j++){
			V[i][j] = V[i-1][j];
			if(j >= 1) V[i][j] = (V[i][j] + V[i-1][j-1] * j * 2) % mod;
			if(j >= 2) V[i][j] = (V[i][j] + V[i-1][j-2] * (j * (j-1) / 2)) % mod;
		}
	}
	
	for(i=0;i<=n;i++){
		for(j=1;j<=m;j++){
			H[i][j] = H[i][j-1];
			if(i >= 1) H[i][j] = (H[i][j] + H[i-1][j-1] * i * 2) % mod;
			if(i >= 2) H[i][j] = (H[i][j] + H[i-2][j-1] * (i * (i-1) / 2)) % mod;
		}
	}
	
	for(i=0;i<=n;i++){
		for(j=0;j<=m;j++){
			ans = (ans + V[i][j] * H[n-i][m-j] % mod * D[n][i] % mod * D[m][j] % mod) % mod;
		}
	}
	
	printf("%lld\n", (ans - 1 + mod) % mod);
	
	return 0;
}

Compilation message

tents.cpp: In function 'int main()':
tents.cpp:17:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld%lld", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~~~~

Subtask #1

48.0 / 48.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	376 KB	Output is correct
2	Correct	3 ms	1252 KB	Output is correct
3	Correct	2 ms	1252 KB	Output is correct
4	Correct	5 ms	3196 KB	Output is correct
5	Correct	5 ms	3196 KB	Output is correct
6	Correct	8 ms	3824 KB	Output is correct
7	Correct	5 ms	3824 KB	Output is correct
8	Correct	6 ms	4160 KB	Output is correct
9	Correct	4 ms	4160 KB	Output is correct
10	Correct	8 ms	5040 KB	Output is correct
11	Correct	4 ms	5040 KB	Output is correct
12	Correct	11 ms	5984 KB	Output is correct

Subtask #2

52.0 / 52.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	376 KB	Output is correct
2	Correct	3 ms	1252 KB	Output is correct
3	Correct	2 ms	1252 KB	Output is correct
4	Correct	5 ms	3196 KB	Output is correct
5	Correct	5 ms	3196 KB	Output is correct
6	Correct	8 ms	3824 KB	Output is correct
7	Correct	5 ms	3824 KB	Output is correct
8	Correct	6 ms	4160 KB	Output is correct
9	Correct	4 ms	4160 KB	Output is correct
10	Correct	8 ms	5040 KB	Output is correct
11	Correct	4 ms	5040 KB	Output is correct
12	Correct	11 ms	5984 KB	Output is correct
13	Correct	22 ms	21216 KB	Output is correct
14	Correct	50 ms	49504 KB	Output is correct
15	Correct	300 ms	151116 KB	Output is correct
16	Correct	34 ms	151116 KB	Output is correct
17	Correct	82 ms	151116 KB	Output is correct
18	Correct	91 ms	151116 KB	Output is correct
19	Correct	351 ms	170152 KB	Output is correct
20	Correct	249 ms	170152 KB	Output is correct
21	Correct	189 ms	170152 KB	Output is correct
22	Correct	176 ms	170152 KB	Output is correct
23	Correct	139 ms	170152 KB	Output is correct
24	Correct	441 ms	189348 KB	Output is correct
25	Correct	340 ms	189348 KB	Output is correct
26	Correct	407 ms	189348 KB	Output is correct
27	Correct	417 ms	189348 KB	Output is correct