Submission #69120

#	Time	Username	Problem	Language	Result	Execution time	Memory
69120		MatheusLealV	Portals (BOI14_portals)	C++17	70 / 100	1101 ms	139464 KiB

portals

#include <bits/stdc++.h>
#define N 1050
#define f first
#define s second
using namespace std;
typedef pair<int, int> pii;

int n, m, xo, yo, xi, yi, dx[4] = {1, -1, 0, 0}, dy[4] = {0, 0, 1, -1};

int id[N][N], cnt, dist[N*N], pai[N*N];

pii O[N];

char mat[N][N];

vector<pii> grafo[N*N];

int solve(int ini, int fim)
{
	priority_queue<pii, vector<pii>, greater<pii> > fila;

	memset(dist, 0x3f3f3f3f, sizeof dist);

	dist[ini] = 0;

	fila.push({0, ini});

	while(!fila.empty())
	{
		int x = fila.top().s, d = fila.top().s;

		fila.pop();

		for(auto v: grafo[x])
		{
			if(dist[v.f] > dist[x] + v.s)
			{
				dist[v.f] = dist[x] + v.s;

				pai[v.f] = x;

				fila.push({dist[v.f], v.f});
			}
		}
	}

	int u = fim;

	// while(true)
	// {
	// 	int x = O[u].f, y = O[u].s;

	// 	cout<<"at position "<<x<<" "<<y<<"\n";

	// 	if(u == ini) break;

	// 	u = pai[u];
	// }

	return dist[fim];
}

int main()
{
	ios::sync_with_stdio(false); cin.tie(0);

	cin>>n>>m;

	for(int i = 0; i <= n + 1; i++)
	{
		for(int j = 0; j <= m + 1; j++)
		{
			id[i][j] = ++ cnt;

			O[id[i][j]] = {i, j};
		}
	}

	for(int i = 0; i <= n + 1; i++)
		for(int j = 0; j <= m + 1; j++)
		{
			if(!i or i == n + 1 or !j or j == m + 1)
			{
				mat[i][j] = '#';

				continue;
			}

			cin>>mat[i][j];

			if(mat[i][j] == 'S') xo = i, yo = j;

			if(mat[i][j] == 'C') xi = i, yi = j;
		}

	for(int i = 1; i <= n; i++)
	{
		for(int j = 1; j <= m; j++)
		{
			int x = id[i][j];

			if(mat[i][j] != '#')
			{
				for(int p = 0; p < 4; p++)
				{
					int a = i + dx[p], b = j + dy[p];

					if(a < 0 or b < 0 or a > n + 1 or b > m + 1) continue;

					 if(mat[a][b] != '#') grafo[x].push_back({id[a][b], 1}); 
				}
			}
		}
	}

	for(int i = 1; i <= n; i++)
	{
		for(int j = 1; j <= m; j++)
		{
			if(mat[i][j] == '#') continue;

			vector< pii > pos;

			for(int z = j; z > 0; z--)
			{
				if(mat[i][z] == '#') break;

				if(mat[i][z - 1] == '#' and mat[i][z] != '#')
				{
					pos.push_back({i, z});

					break;
				}
			}

			for(int z = j; z <= m; z ++)
			{
				if(mat[i][z] == '#') break;

				if(mat[i][z + 1] == '#' and mat[i][z] != '#')
				{
					pos.push_back({i, z});

					break;
				}
			}

			for(int z = i; z <= n; z ++)
			{
				if(mat[z][j] == '#') break;

				if(mat[z + 1][j] == '#' and mat[z][j] != '#')
				{
					pos.push_back({z, j});

					break;
				}
			}

			for(int z = i; z > 0; z --)
			{
				if(mat[z][j] == '#') break;

				if(mat[z - 1][j] == '#' and mat[z][j] != '#')
				{
					pos.push_back({z, j});

					break;
				}
			}

			int x = id[i][j];

			for(int a = 0; a < pos.size(); a++)
			{
				for(int b = 0; b < pos.size(); b++)
				{
					if(a == b) continue;

					int A = abs(i - pos[a].f) + abs(j - pos[a].s), B = abs(i - pos[b].f) + abs(j - pos[b].s);

					int custo = min(A, B) + 1;

					 grafo[x].push_back({id[pos[a].f][pos[a].s], custo});

					// grafo[id[pos[b].f][pos[b].s]].push_back({id[pos[a].f][pos[a].s], custo});

					//cout<<"GRAFO "<<i<<" "<<j<<"   "<<pos[a].f<<" "<<pos[a].s<<"    "<<pos[b].f<<" "<<pos[b].s<<" "<<custo<<"\n";
				}
			}
		}
	}

	cout<<solve(id[xo][yo], id[xi][yi])<<"\n";
}

Compilation message (stderr)

portals.cpp: In function 'int solve(int, int)':
portals.cpp:30:25: warning: unused variable 'd' [-Wunused-variable]
   int x = fila.top().s, d = fila.top().s;
                         ^
portals.cpp:47:6: warning: unused variable 'u' [-Wunused-variable]
  int u = fim;
      ^
portals.cpp: In function 'int main()':
portals.cpp:174:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int a = 0; a < pos.size(); a++)
                   ~~^~~~~~~~~~~~
portals.cpp:176:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int b = 0; b < pos.size(); b++)
                    ~~^~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 19 / 19
• Subtask 5: 0 / 30