Submission #93516

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
93516	2019-01-09T07:50:43 Z	vatsalsharma376	Tents (JOI18_tents)	C++14	100 / 100	113 ms	70776 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	512 KB	Output is correct
2	Correct	1 ms	256 KB	Output is correct
3	Correct	2 ms	504 KB	Output is correct
4	Correct	2 ms	1144 KB	Output is correct
5	Correct	2 ms	760 KB	Output is correct
6	Correct	2 ms	1400 KB	Output is correct
7	Correct	2 ms	760 KB	Output is correct
8	Correct	2 ms	1528 KB	Output is correct
9	Correct	2 ms	888 KB	Output is correct
10	Correct	3 ms	1784 KB	Output is correct
11	Correct	2 ms	376 KB	Output is correct
12	Correct	3 ms	2168 KB	Output is correct

Subtask #2

52.0 / 52.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	512 KB	Output is correct
2	Correct	1 ms	256 KB	Output is correct
3	Correct	2 ms	504 KB	Output is correct
4	Correct	2 ms	1144 KB	Output is correct
5	Correct	2 ms	760 KB	Output is correct
6	Correct	2 ms	1400 KB	Output is correct
7	Correct	2 ms	760 KB	Output is correct
8	Correct	2 ms	1528 KB	Output is correct
9	Correct	2 ms	888 KB	Output is correct
10	Correct	3 ms	1784 KB	Output is correct
11	Correct	2 ms	376 KB	Output is correct
12	Correct	3 ms	2168 KB	Output is correct
13	Correct	2 ms	376 KB	Output is correct
14	Correct	7 ms	9592 KB	Output is correct
15	Correct	72 ms	55160 KB	Output is correct
16	Correct	7 ms	4060 KB	Output is correct
17	Correct	19 ms	12792 KB	Output is correct
18	Correct	24 ms	17144 KB	Output is correct
19	Correct	90 ms	63048 KB	Output is correct
20	Correct	74 ms	50936 KB	Output is correct
21	Correct	50 ms	33728 KB	Output is correct
22	Correct	50 ms	35420 KB	Output is correct
23	Correct	33 ms	27112 KB	Output is correct
24	Correct	113 ms	70776 KB	Output is correct
25	Correct	91 ms	61176 KB	Output is correct
26	Correct	102 ms	66552 KB	Output is correct
27	Correct	110 ms	68900 KB	Output is correct