Submission #163720

#	Time	Username	Problem	Language	Result	Execution time	Memory
163720		MvC	Kangaroo (CEOI16_kangaroo)	C++11	0 / 100	2 ms	376 KiB

kangaroo

#pragma GCC target("avx2")
#pragma GCC optimization("O3")
#pragma GCC optimization("unroll-loops")
#include <bits/stdc++.h>
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define mkp make_pair
#define in insert
#define er erase
#define fd find
#define fr first
#define sc second
typedef long long ll;
typedef long double ld;
const ll INF=0x3f3f3f3f3f3f3f3f;
const ll llinf=(1LL<<62);
const int inf=(1<<30);
const int nmax=2e2+50;
const int mod=1e9+7;
using namespace std;
int f[nmax][nmax][2][nmax][2],n,cs,cf,t,k,i,j,rs;
void ad(int &x,int y)
{
	x+=y;
	if(x>=mod)x-=mod;
}
int main()
{
	//freopen("sol.in","r",stdin);
	//freopen("sol.out","w",stdout);
	//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
	ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
	cin>>n>>cs>>cf;
	f[1][0][0][0][0]=f[1][0][0][0][1]=f[1][0][1][0][0]=f[1][0][1][0][1]=1;
	for(t=1;t<n;t++)
	{
		// left occupied
		for(k=0;k<=min(t,cs-1);k++)
		{
			// left
			for(i=0;i<=cs-1-k+1;i++)
			{
				// -->
				for(j=1;j<i;j++)
				{
					ad(f[t+1][k+1][0][j][0],f[t][k][0][i][1]);
					//cout<<f[t][k][0][i][1]<<endl;
				}
				for(j=1;j<=n-cs-(t-k)+1;j++)
				{
					ad(f[t+1][k][1][j][0],f[t][k][0][i][1]);
					//cout<<f[t][k][0][i][1]<<endl;
				}
				// <--
				for(j=i+1;j<=cs-1-k+1;j++)
				{
					ad(f[t+1][k+1][0][j][1],f[t][k][0][i][0]);
					//cout<<f[t][k][0][i][0]<<endl;
				}
			}
			// right
			for(i=0;i<=n-cs-(t-k)+1;i++)
			{
				// <--
				for(j=1;j<i;j++)
				{
					ad(f[t+1][k][1][j][1],f[t][k][1][i][0]);
					//cout<<f[t][k][1][i][0]<<endl;
				}
				for(j=1;j<=cs-1-k+1;j++)
				{
					ad(f[t+1][k+1][0][j][1],f[t][k][1][i][0]);
					//cout<<f[t][k][1][i][0]<<endl;
				}
				// -->
				for(j=i+1;j<=n-cs-(t-k)+1;j++)
				{
					ad(f[t+1][k][1][j][0],f[t][k][1][i][1]);
					//cout<<f[t][k][1][i][1]<<endl;
				}
			}
		}
	}
	if(cf>cs)rs=(f[n][cs-1][1][cf-cs][0]+f[n][cs-1][1][cf-cs][1])%mod;
	else rs=(f[n][cs-1][0][cs-cf][0]+f[n][cs-1][0][cs-cf][1])%mod;
	cout<<rs<<endl;
	return 0;
}

Compilation message (stderr)

kangaroo.cpp:2:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization("O3")
 
kangaroo.cpp:3:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization("unroll-loops")

• Subtask 1: 0 / 6
• Subtask 2: 0 / 30
• Subtask 3: 0 / 15
• Subtask 4: 0 / 49