Submission #43966

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
43966	2018-03-29T01:15:50 Z	model_code	Tents (JOI18_tents)	C++17	100 / 100	119 ms	71204 KB

tents

#include<cstdio>
#include<algorithm>

using namespace std;

const long long mod = 1000000007;

const int MAX_N = 3000;

long long dp[MAX_N + 1][MAX_N + 1];

int H, W;

long long C2(int x){
	return x * (x - 1) / 2;
}

long long solve(){
	for(int i = 0; i <= H; ++i){
		for(int j = 0; j <= W; ++j){
			if(i == 0 || j == 0){
				dp[i][j] = 1;
			}else{
				dp[i][j] = 0;
				dp[i][j] += dp[i][j - 1];
				dp[i][j] += 4ll * i * dp[i - 1][j - 1];
				if(i >= 2){
					long long tmp = C2(i);
					dp[i][j] += tmp * dp[i - 2][j - 1];
				}
				if(j >= 2){
					dp[i][j] += (long long)i * (j - 1) * dp[i - 1][j - 2];
				}
				dp[i][j] %= mod;
			}
		}
	}
	long long ans = dp[H][W] - 1;
	ans %= mod;
	ans += mod;
	ans %= mod;
	return ans;
}

int main(){
	scanf("%d%d", &H, &W);
	long long ans = solve();
	printf("%lld\n", ans);
	return 0;
}

Compilation message

tents.cpp: In function 'int main()':
tents.cpp:46:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &H, &W);
  ~~~~~^~~~~~~~~~~~~~~~

Subtask #1

48.0 / 48.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	376 KB	Output is correct
2	Correct	2 ms	488 KB	Output is correct
3	Correct	2 ms	564 KB	Output is correct
4	Correct	2 ms	1288 KB	Output is correct
5	Correct	2 ms	1288 KB	Output is correct
6	Correct	3 ms	1668 KB	Output is correct
7	Correct	2 ms	1668 KB	Output is correct
8	Correct	2 ms	1668 KB	Output is correct
9	Correct	2 ms	1668 KB	Output is correct
10	Correct	3 ms	1936 KB	Output is correct
11	Correct	2 ms	1936 KB	Output is correct
12	Correct	3 ms	2400 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	2 ms	488 KB	Output is correct
3	Correct	2 ms	564 KB	Output is correct
4	Correct	2 ms	1288 KB	Output is correct
5	Correct	2 ms	1288 KB	Output is correct
6	Correct	3 ms	1668 KB	Output is correct
7	Correct	2 ms	1668 KB	Output is correct
8	Correct	2 ms	1668 KB	Output is correct
9	Correct	2 ms	1668 KB	Output is correct
10	Correct	3 ms	1936 KB	Output is correct
11	Correct	2 ms	1936 KB	Output is correct
12	Correct	3 ms	2400 KB	Output is correct
13	Correct	2 ms	2400 KB	Output is correct
14	Correct	7 ms	9896 KB	Output is correct
15	Correct	80 ms	55532 KB	Output is correct
16	Correct	7 ms	55532 KB	Output is correct
17	Correct	20 ms	55532 KB	Output is correct
18	Correct	25 ms	55532 KB	Output is correct
19	Correct	92 ms	63328 KB	Output is correct
20	Correct	81 ms	63328 KB	Output is correct
21	Correct	50 ms	63328 KB	Output is correct
22	Correct	49 ms	63328 KB	Output is correct
23	Correct	35 ms	63328 KB	Output is correct
24	Correct	119 ms	71204 KB	Output is correct
25	Correct	92 ms	71204 KB	Output is correct
26	Correct	105 ms	71204 KB	Output is correct
27	Correct	112 ms	71204 KB	Output is correct