Submission #116647

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
116647	2019-06-13T10:02:48 Z	roseanne_pcy	Tents (JOI18_tents)	C++14	100 / 100	383 ms	35992 KB

tents

#include <bits/stdc++.h>
using namespace std;
const int md = 1e9+7;
const int maxn = 3e3+5;
int dp[maxn][maxn];
void add(int &a, int b)
{
    a += b;
    if(a>= md) a-= md;
}
int mul(int a, int b)
{
    return (1LL*a*b)%md;
}
int solve(int n, int m)
{
    if(n == 0 || m == 0) return 1;
    if(dp[n][m] != -1) return dp[n][m];
    int &res = dp[n][m];
    res = 0;
    add(res, mul(4*m, solve(n-1, m-1)));
    if(n>= 2) add(res, mul(m*(n-1), solve(n-2, m-1)));
    if(m>= 2) add(res, mul(m*(m-1)/2, solve(n-1, m-2)));
    add(res, solve(n-1, m));
    return res;
}
int main()
{
    int n, m; cin >> n >> m;
    memset(dp, -1, sizeof dp);
    cout << solve(n, m)-1 << endl;
}

Subtask #1

48.0 / 48.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	30 ms	35704 KB	Output is correct
2	Correct	30 ms	35712 KB	Output is correct
3	Correct	30 ms	35704 KB	Output is correct
4	Correct	28 ms	35716 KB	Output is correct
5	Correct	30 ms	35704 KB	Output is correct
6	Correct	29 ms	35704 KB	Output is correct
7	Correct	29 ms	35704 KB	Output is correct
8	Correct	31 ms	35676 KB	Output is correct
9	Correct	29 ms	35624 KB	Output is correct
10	Correct	30 ms	35704 KB	Output is correct
11	Correct	31 ms	35708 KB	Output is correct
12	Correct	32 ms	35676 KB	Output is correct

Subtask #2

52.0 / 52.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	30 ms	35704 KB	Output is correct
2	Correct	30 ms	35712 KB	Output is correct
3	Correct	30 ms	35704 KB	Output is correct
4	Correct	28 ms	35716 KB	Output is correct
5	Correct	30 ms	35704 KB	Output is correct
6	Correct	29 ms	35704 KB	Output is correct
7	Correct	29 ms	35704 KB	Output is correct
8	Correct	31 ms	35676 KB	Output is correct
9	Correct	29 ms	35624 KB	Output is correct
10	Correct	30 ms	35704 KB	Output is correct
11	Correct	31 ms	35708 KB	Output is correct
12	Correct	32 ms	35676 KB	Output is correct
13	Correct	49 ms	35704 KB	Output is correct
14	Correct	29 ms	35832 KB	Output is correct
15	Correct	284 ms	35832 KB	Output is correct
16	Correct	31 ms	35704 KB	Output is correct
17	Correct	44 ms	35708 KB	Output is correct
18	Correct	77 ms	35704 KB	Output is correct
19	Correct	347 ms	35932 KB	Output is correct
20	Correct	237 ms	35920 KB	Output is correct
21	Correct	125 ms	35832 KB	Output is correct
22	Correct	146 ms	35872 KB	Output is correct
23	Correct	126 ms	35960 KB	Output is correct
24	Correct	383 ms	35924 KB	Output is correct
25	Correct	278 ms	35992 KB	Output is correct
26	Correct	326 ms	35832 KB	Output is correct
27	Correct	360 ms	35960 KB	Output is correct