Submission #236878

#	Time	Username	Problem	Language	Result	Execution time	Memory
236878		nishkarsh	Tents (JOI18_tents)	C++14	100 / 100	244 ms	70904 KiB

tents

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pcc pair<char,char>
#define vi vector <int>
#define vl vector <ll>
#define sd(x) scanf("%d",&x)
#define slld(x) scanf("%lld",&x)
#define pd(x) printf("%d",x)
#define plld(x) printf("%lld",x)
#define pds(x) printf("%d ",x)
#define pllds(x) printf("%lld ",x)
#define pdn(x) printf("%d\n",x)
#define plldn(x) printf("%lld\n",x)
#define INF 2e9
#define INFLL 4e18
using namespace std;
ll powmod(ll base,ll exponent,ll mod){ // with mod < 1e9
	ll ans=1;
	while(exponent){
		if(exponent&1)ans=(ans*base)%mod;
		base=(base*base)%mod;
		exponent/=2;
	}
	return ans;
}
ll gcd(ll a, ll b){
	if(b==0) return a;
	else return gcd(b,a%b);
}
const int upperlimit = 3e3+1;
const int mod = 1e9+7;
ll dp[upperlimit][upperlimit];
int main() {
//	freopen(".in","r",stdin);freopen(".out","w",stdout);
	for(int i = 0; i < upperlimit; i++){
		dp[i][0]=dp[0][i]=1;
	}
	for(int i = 1; i < upperlimit; i++){
		dp[i][1]=dp[1][i]=((i*(i-1))/2)+(4*i)+1;
	}
	for(int i = 2; i < upperlimit; i++){
		for(int j = 2; j < upperlimit; j++){
			dp[i][j]=4*dp[i-1][j-1];
			ll calc=i-1;calc*=dp[i-2][j-1];calc%=mod;
			dp[i][j]+=calc;dp[i][j]%=mod;
			calc=j-1;calc*=dp[i-1][j-2];calc%=mod;
			dp[i][j]+=calc;dp[i][j]%=mod;
			calc=i-1;calc*=i-2;calc>>=1;calc*=dp[i-2][j-1];calc%=mod;
			dp[i][j]+=calc;dp[i][j]%=mod;
			calc=i-1;calc*=4;calc*=dp[i-1][j-1];calc%=mod;
			dp[i][j]+=calc;dp[i][j]%=mod;
			calc=i-1;calc*=j-1;calc*=dp[i-1][j-2];calc%=mod;
			dp[i][j]+=calc;dp[i][j]%=mod;
			dp[i][j]+=dp[i][j-1];dp[i][j]%=mod;
		}
	}
	int h,w;
	sd(h);sd(w);
	plld(dp[h][w]-1);
	return 0;
}

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:12:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 #define sd(x) scanf("%d",&x)
               ~~~~~^~~~~~~~~
tents.cpp:64:2: note: in expansion of macro 'sd'
  sd(h);sd(w);
  ^~
tents.cpp:12:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 #define sd(x) scanf("%d",&x)
               ~~~~~^~~~~~~~~
tents.cpp:64:8: note: in expansion of macro 'sd'
  sd(h);sd(w);
        ^~

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