Submission #363284

#	Time	Username	Problem	Language	Result	Execution time	Memory
363284		r57shell	Cats or Dogs (JOI18_catdog)	C++14	0 / 100	2 ms	2668 KiB

catdog

#include "catdog.h"
#include <array>

using namespace std;

const int MAXN = 1e5;

static vector<int> E[MAXN+2];
static int pet[MAXN+2];
static int N;

void initialize(int N, vector<int> A, vector<int> B)
{
	N = A.size();
	for (int i = 0; i < N - 1; ++i)
	{
		E[A[i]].push_back(B[i]);
		E[B[i]].push_back(A[i]);
	}
}

typedef array<int, 3> dpt;

dpt rec(int x, int p)
{
	/*vector<dpt> dd(v);
	for (int i = 0; i < E[x].size(); ++i)
	{
		int v = E[x][i];
		if (v != p)
			dd[i] = rec(v, p);
	}*/
	dpt res;
	res[0] = 0;
	res[1] = 0;
	res[2] = 0;
	for (int i = 0; i < E[x].size(); ++i)
	{
		int v = E[x][i];
		if (v != p)
		{
			dpt dp = rec(v, x);
			res[0] += min(dp[0], min(dp[1], dp[2]) + 1);
			res[1] += min(dp[1], min(dp[0], dp[2] + 1));
			res[2] += min(dp[2], min(dp[0], dp[1] + 1));
			res[0] = min(res[0], int(1e8));
			res[1] = min(res[1], int(1e8));
			res[2] = min(res[2], int(1e8));
		}
	}
	if (pet[x] == 1)
	{
		res[0] = int(1e8);
		res[2] = int(1e8);
	}
	else if (pet[x] == 2)
	{
		res[0] = int(1e8);
		res[1] = int(1e8);
	}
	//printf("%d %d (%d %d %d)\n", x, p, res[0], res[1], res[2]);
	return res;
}

static int solve()
{
	dpt res = rec(1, -1);
	int ans = min(res[0], min(res[1], res[2]));;
	//printf("ans = %d\n", ans);
	return ans;
}

int cat(int v)
{
	pet[v] = 1;
	return solve();
}

int dog(int v)
{
	pet[v] = 2;
	return solve();
}

int neighbor(int v)
{
	pet[v] = 0;
	return solve();
}

Compilation message (stderr)

catdog.cpp: In function 'dpt rec(int, int)':
catdog.cpp:37:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |  for (int i = 0; i < E[x].size(); ++i)
      |                  ~~^~~~~~~~~~~~~
catdog.cpp: At global scope:
catdog.cpp:10:12: warning: 'N' defined but not used [-Wunused-variable]
   10 | static int N;
      |            ^

• Subtask 1: 0 / 8
• Subtask 2: 0 / 30
• Subtask 3: 0 / 62