Submission #100777

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
100777	2019-03-14T09:57:57 Z	TAISA_	Tents (JOI18_tents)	C++14	100 / 100	175 ms	71416 KB

tents

#include<bits/stdc++.h>
#define all(vec) vec.begin(),vec.end()
using namespace std;
using ll=long long;
const ll MOD=1000000007LL;
template<typename T> void chmax(T &a,T b){a=max(a,b);}
template<typename T> void chmin(T &a,T b){a=min(a,b);} 
vector<ll> f,fi;
ll mpow(ll x,ll n){
	ll res=1;
	while(n>0){
		if(n&1){
			res*=x;
			res%=MOD;
		}
		x*=x;
		x%=MOD;
		n>>=1;
	}
	return res;
}
void comb(ll n){
	f.resize(n+10);
	fi.resize(n+10);
	f[0]=1;
	for(ll i=1;i<=n;i++){
		f[i]=f[i-1]*i%MOD;
	}
	fi[n]=mpow(f[n],MOD-2);
	for(ll i=n-1;i>=0;i--){
		fi[i]=fi[i+1]*(i+1LL)%MOD;
	}
}
ll ncr(ll n,ll r){
	return f[n]*fi[r]%MOD*fi[n-r]%MOD;
}
int main(){
	ll h,w;cin>>h>>w;
	comb(h+w);
	vector<vector<ll>> dp(h+10,vector<ll>(w+10));
	dp[0][w]=1;
	for(ll i=1;i<=h;i++){
		for(ll j=0;j<=w;j++){
			dp[i][j]+=dp[i-1][j];
			if(j<w){
				dp[i][j]+=dp[i-1][j+1]*(j+1LL)%MOD*4LL%MOD;
				if(j<w-1){
					dp[i][j]+=dp[i-1][j+2]*((j+2LL)*(j+1LL)/2LL)%MOD;
				}
			}
			dp[i][j]%=MOD;
		}
	}
	ll ans=0;
	for(ll i=0;i<=h/2;i++){//横かぶりの個数
		ll s=1;
		for(ll j=h;j>h-i*2;j-=2){
			s*=ncr(j,2);
			s%=MOD;
		}
		for(ll j=0;j<=w;j++){//残り列数
			if(i==0&&j==w)continue;
			if(j<i)continue;
			ans+=dp[h-i*2][j]*s%MOD*ncr(j,i)%MOD;
			ans%=MOD;
		}
	}
	cout<<ans<<endl;
}

Subtask #1

48.0 / 48.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	384 KB	Output is correct
2	Correct	3 ms	384 KB	Output is correct
3	Correct	6 ms	256 KB	Output is correct
4	Correct	2 ms	384 KB	Output is correct
5	Correct	2 ms	512 KB	Output is correct
6	Correct	3 ms	512 KB	Output is correct
7	Correct	2 ms	512 KB	Output is correct
8	Correct	2 ms	512 KB	Output is correct
9	Correct	2 ms	384 KB	Output is correct
10	Correct	3 ms	640 KB	Output is correct
11	Correct	2 ms	384 KB	Output is correct
12	Correct	4 ms	1024 KB	Output is correct

Subtask #2

52.0 / 52.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	384 KB	Output is correct
2	Correct	3 ms	384 KB	Output is correct
3	Correct	6 ms	256 KB	Output is correct
4	Correct	2 ms	384 KB	Output is correct
5	Correct	2 ms	512 KB	Output is correct
6	Correct	3 ms	512 KB	Output is correct
7	Correct	2 ms	512 KB	Output is correct
8	Correct	2 ms	512 KB	Output is correct
9	Correct	2 ms	384 KB	Output is correct
10	Correct	3 ms	640 KB	Output is correct
11	Correct	2 ms	384 KB	Output is correct
12	Correct	4 ms	1024 KB	Output is correct
13	Correct	3 ms	512 KB	Output is correct
14	Correct	6 ms	640 KB	Output is correct
15	Correct	110 ms	44664 KB	Output is correct
16	Correct	13 ms	3328 KB	Output is correct
17	Correct	30 ms	10368 KB	Output is correct
18	Correct	31 ms	12672 KB	Output is correct
19	Correct	127 ms	51832 KB	Output is correct
20	Correct	128 ms	41848 KB	Output is correct
21	Correct	69 ms	27644 KB	Output is correct
22	Correct	69 ms	27404 KB	Output is correct
23	Correct	43 ms	15480 KB	Output is correct
24	Correct	168 ms	71416 KB	Output is correct
25	Correct	154 ms	53240 KB	Output is correct
26	Correct	157 ms	60968 KB	Output is correct
27	Correct	175 ms	68748 KB	Output is correct