Submission #204527

#	Time	Username	Problem	Language	Result	Execution time	Memory
204527		Atill83	Tents (JOI18_tents)	C++14	100 / 100	391 ms	71420 KiB

tents

#include <bits/stdc++.h>
#define ff first
#define ss second
#define endl '\n'
using namespace std;
const long long INF = (long long) 1e18;
const int mod = (int) 1e9+7;
const int MAXN = (int) 3e5+5;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
ll n;
ll comb[10005];
ll dp[3005][3005];
ll do_it(ll satir, ll sutun){
    if(dp[satir][sutun] != -1) return dp[satir][sutun];
    if(sutun < 0 || satir < 0) return 0;
    if(satir <= 0){
        return 1;
    }
    ll ans = 0;
    ans = (ans + comb[sutun]*do_it(satir - 1, sutun - 2)%mod)%mod;
    ans = (ans + sutun*(satir - 1)%mod*do_it(satir - 2, sutun - 1)%mod)%mod;
    ans = (ans + 4*sutun*do_it(satir - 1, sutun - 1)%mod)%mod;
    ans = (ans + do_it(satir - 1, sutun))%mod;
    return dp[satir][sutun] = ans;
}




int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);cout.tie(nullptr);

    #ifdef Local
        freopen("C:/Users/Admin/Desktop/Yazilim/C/IO/int.txt","r",stdin);
        freopen("C:/Users/Admin/Desktop/Yazilim/C/IO/out.txt","w",stdout);
    #endif
    ll W, H;
    cin>>W>>H;
    memset(dp, -1, sizeof(dp));

    for(int i = 2; i <= 1e4; i++){
        comb[i] = i*(i - 1) / 2;
    }
    cout<< (do_it(H, W) - 1 + mod) % mod;


    #ifdef Local
        cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
    #endif
}

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