Submission #638398

#	Time	Username	Problem	Language	Result	Execution time	Memory
638398		urosk	Tents (JOI18_tents)	C++14	100 / 100	299 ms	70864 KiB

tents

#define here cerr<<"===========================================\n"
#define dbg(x) cerr<<#x<<": "<<x<<endl;
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#define ld double
#define ll long long
#define llinf 100000000000000000LL // 10^17
#define pb push_back
#define popb pop_back
#define fi first
#define sc second
#define endl '\n'
#define pll pair<ll,ll>
#define pld pair<ld,ld>
#define sz(a) (ll)(a.size())
#define all(a) a.begin(),a.end()
#define ceri(a,l,r) {cerr<<#a<<": ";for(ll i_ = l;i_<=r;i_++) cerr<<a[i_]<< " ";cerr<<endl;}
#define daj_mi_malo_vremena ios_base::sync_with_stdio(false);cerr.tie(0);cout.tie(0);cin.tie(0);

using namespace std;
using namespace __gnu_pbds;
#define mod 1000000007

ll add(ll x,ll y){
    x+=y;
    if(x<0){
        x%=mod;
        x+=mod;
    }else{
        if(x>=mod) x%=mod;
    }
    return x;
}
ll mul(ll a,ll b){
	ll ans = (a*b)%mod;
	if(ans<0) ans+=mod;
	return ans;
}
ll po(ll x,ll y){
    if(y==0) return 1LL;
    ll ans = po(x,y/2);
    ans = mul(ans,ans);
    if(y&1) ans = mul(ans,x);
    return ans;
}
ll inv(ll x){return po(x,mod-2);}
ll ch(ll x){
    return mul(mul(x,x-1),inv(2));
}
#define maxn 3005
ll n,m;
ll dp[maxn][maxn];
void tc(){
    cin >> n >> m;
    for(ll i = 0;i<maxn;i++) dp[i][0] = dp[0][i] = 1;
    for(ll i = 1;i<=n;i++){
        for(ll j = 1;j<=m;j++){
            dp[i][j] = add(dp[i][j],dp[i-1][j]);
            dp[i][j] = add(dp[i][j],mul(dp[i-1][j-1],4*j));
            if(i>=2) dp[i][j] = add(dp[i][j],mul(dp[i-2][j-1],mul(j,i-1)));
            if(j>=2) dp[i][j] = add(dp[i][j],mul(dp[i-1][j-2],j*(j-1)/2));
        }
    }
    dp[n][m] = add(dp[n][m],-1);
    cout<<dp[n][m]<<endl;
}
int main(){
	daj_mi_malo_vremena
    int t; t = 1;
    while(t--){
        tc();
    }
	return 0;
}

• Subtask 1: 48 / 48
• Subtask 2: 52 / 52