Submission #79119

#	Time	Username	Problem	Language	Result	Execution time	Memory
79119		psmao	Sailing Race (CEOI12_race)	C++14	100 / 100	547 ms	6000 KiB

race

#include <bits/stdc++.h>
using namespace std;

#define fo(i,s,t) for(int i = s; i <= t; ++ i)
#define fd(i,s,t) for(int i = s; i >= t; -- i)
#define bf(i,s) for(int i = head[s]; i; i = e[i].next)
#define mp make_pair
#define fi first
#define se second
#define pii pair<int,int>
#define pb push_back
#define VI vector<int>
#define sf scanf
#define pf printf
#define fp freopen
#define SZ(x) ((int)(x).size())
#ifdef MPS
#define D(x...) printf(x)
#else
#define D(x...)
#endif
typedef long long ll;
typedef double db;
typedef unsigned long long ull;
const int inf = 1<<30;
const ll INF = 1ll<<60;
const db Inf = 1e20;
const db eps = 1e-9;

void gmax(int &a,int b){a = (a > b ? a : b);}
void gmin(int &a,int b){a = (a < b ? a : b);}

const int maxn = 505;

int f[maxn][maxn], g[maxn][maxn], md[maxn][maxn], mdc[maxn][maxn], n, sub;
VI adj[maxn], radj[maxn];

int dis(int x, int y)
{
	if(x > y) swap(x, y);
	return min(y-x, n-(y-x));
}
int main()
{
	#ifdef MPS
		fp("1.in","r",stdin);
		fp("1.out","w",stdout);
		db mps = clock();
	#endif
	sf("%d%d",&n,&sub);
	fo(i,1,n) fo(j,1,n) md[i][j] = mdc[i][j] = -inf;
	fo(i,1,n)
	{
		int x;
		while(1)
		{
			sf("%d",&x);
			if(!x) break;
			adj[i].pb(x);
			radj[x].pb(i);
			md[i][x] = mdc[i][x] = 1;
		}
	}
	fo(len,2,n)
	{
		fo(i,1,n)
		{
			int j = i+len-1;
			if(j > n) j = j - n;
			for(auto k : adj[i])
			{
				if(i < j)
				{
					if(k >= i && k < j) 
					{
						gmax(f[i][j], 1 + max(f[k][j], g[k][i]));
						gmax(md[i][j], 1 + md[k][j]);
					}
				}
				else
				{
					if(k >= i || k < j) 
					{
						gmax(f[i][j], 1 + max(f[k][j], g[k][i]));
						gmax(md[i][j], 1 + md[k][j]);
					}
				}
			}
			for(auto k : adj[j])
			{
				if(i < j)
				{
					if(k > i && k <= j) 
					{
						gmax(g[j][i], 1 + max(g[k][i], f[k][j]));
						gmax(mdc[j][i], 1 + mdc[k][i]);
					}
				}
				else
				{
					if(k > i || k <= j) 
					{
						gmax(g[j][i], 1 + max(g[k][i], f[k][j]));
						gmax(mdc[j][i], 1 + mdc[k][i]);
					}
				}
			}	
			D("%d %d %d %d\n",i,j,md[i][j],mdc[j][i]);
		}
	}
	int ans = 0, target;
	fo(s,1,n) 
		for(auto t : adj[s])
		{
			if(max(f[t][s], g[t][s]) + 1 > ans)
			{
				ans = max(f[t][s], g[t][s]) + 1;
				target = s;
			}
		}
	if(sub == 1)
	{
		fo(C,1,n)
			fo(B,1,n) if(B != C)
 			{
				//case 1 : BAC counterclockwise
 				if(C < B)
 				{
	 				int A = 0;
	 				for(auto x : radj[B]) 
	 					if(x > B || x < C)
	 					{
	 						if(!A || dis(A,C) > dis(x,C))
	 							A = x;
	 					}
	 				if(A) // there is such A existing
	 				{
	 					// we want to find a D
	 					for(auto D : adj[C])
	 					{
	 						if(A > B) // B<A<=N
	 						{
	 							if(D > B && D < A)
	 							{
	 								if(1 + mdc[B][C] + 1 + max(g[D][B], f[D][A]) > ans)
	 								{
	 									ans = 1 + mdc[B][C] + 1 + max(g[D][B], f[D][A]);
	 									target = A;
	 									D("a%d %d %d %d %d\n",A,B,C,D,ans);
	 								}
	 							}
	 						}
	 						else // 1<A<C<B<N
	 						{
	 							if(D < A || D > B)
	 							{
	 								if(1 + mdc[B][C] + 1 + max(g[D][B], f[D][A]) > ans)
	 								{
	 									ans = 1 + mdc[B][C] + 1 + max(g[D][B], f[D][A]);
	 									target = A;
	 									D("b%d %d %d %d %d\n",A,B,C,D,ans);
	 								}
	 							}
	 						}
	 					}
	 				}
	 				A = 0;
	 				for(auto x : radj[B]) 
	 					if(x > C && x < B)
	 					{
	 						if(!A || dis(A,C) > dis(x,C))
	 							A = x;
	 					}
	 				if(A)
	 				{
	 					for(auto D : adj[C])
	 					{
	 						if(D > A && D < B)
	 						{
	 							if(1 + md[B][C] + 1 + max(f[D][B], g[D][A]) > ans)
	 							{
	 								ans = 1 + md[B][C] + 1 + max(f[D][B], g[D][A]);
	 								target = A;
	 								D("c%d %d %d %d %d\n",A,B,C,D,ans);
	 							}
	 						}
	 					}
	 				}
	 			}
				else //case 2 : BAC clockwise
	 			{
	 				int A = 0;
	 				for(auto x : radj[B])
	 					if(x < B || x > C)
	 					{
	 						if(!A || dis(A,C) > dis(x,C))
	 							A = x;
	 					}
	 				if(A)
	 				{
	 					for(auto D : adj[C])
	 					{
	 						if(A > C)
	 						{
	 							if(D < B || D > A)
	 							{
	 								if(1 + md[B][C] + 1 + max(f[D][B], g[D][A]) > ans)
	 								{
	 									ans = 1 + md[B][C] + 1 + max(f[D][B], g[D][A]);
	 									target = A;
	 									D("d%d %d %d %d %d\n",A,B,C,D,ans);
	 								}
	 							}
	 						}
	 						else
	 						{
	 							if(D > A && D < B)
	 							{
	 								if(1 + md[B][C] + 1 + max(f[D][B], g[D][A]) > ans)
	 								{
	 									ans = 1 + md[B][C] + 1 + max(f[D][B], g[D][A]);
	 									target = A;
	 									D("e%d %d %d %d %d\n",A,B,C,D,ans);
	 								}	
	 							}
	 						}
	 					}
	 				}
	 				A = 0;
	 				for(auto x : radj[B])
	 					if(x > B && x < C)
	 					{
	 						if(!A || dis(A,C) > dis(x,C))
	 							A = x;
	 					}
	 				if(A)
	 				{
	 					for(auto D : adj[C])
	 						if(D > B && D < A)
	 						{
	 							if(1 + mdc[B][C] + 1 + max(f[D][A], g[D][B]) > ans)
	 							{
	 								ans = 1 + mdc[B][C] + 1 + max(f[D][A], g[D][B]);
	 								target = A;
	 								D("f%d %d %d %d %d\n",A,B,C,D,ans);
	 							}
	 						}
	 				}
	 			}
			}
	}
	pf("%d\n%d\n",ans,target);
	#ifdef MPS
		pf("Time Elapsed: %.3fms\n",clock()-mps);
	#endif
	return 0;
}

Compilation message (stderr)

race.cpp: In function 'int main()':
race.cpp:50:4: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  sf("%d%d",&n,&sub);
    ^
race.cpp:57:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    sf("%d",&x);
      ^

• Subtask 1: 100 / 100