Submission #1037013

#	Time	Username	Problem	Language	Result	Execution time	Memory
1037013		sssamui	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	538 ms	28804 KiB

tracks

#include <iostream>
#include <cstdio>
#include <vector>
#include <cmath>
#include <queue>
using namespace std;

vector<int> radd = { -1, 0, 1, 0 };
vector<int> cadd = { 0, -1, 0, 1 };

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

	int h, w;
	cin >> h >> w;
	vector<vector<char>> trk(h + 2, vector<char>(w + 2, '.'));
	for (int i = 1; i <= h; i++) for (int j = 1; j <= w; j++) cin >> trk[i][j];

	int ans = 0;
	vector<vector<bool>> vis(h + 2, vector<bool>(w + 2, false));
	queue<pair<int, int>> bfs;
	queue<pair<int, int>> nxt;
	bfs.push({ 1, 1 });
	vis[1][1] = true;
	while (!bfs.empty())
	{
		ans++;
		while (!bfs.empty())
		{
			int r = bfs.front().first, c = bfs.front().second;
			bfs.pop();
			for (int dir = 0; dir < 4; dir++) if (!vis[r + radd[dir]][c + cadd[dir]])
			{
				vis[r + radd[dir]][c + cadd[dir]] = true;
				if (trk[r + radd[dir]][c + cadd[dir]] == trk[r][c]) bfs.push({ r + radd[dir], c + cadd[dir] });
				else if (trk[r + radd[dir]][c + cadd[dir]] != '.') nxt.push({ r + radd[dir], c + cadd[dir] });
			}
		}

		while (!nxt.empty())
		{
			bfs.push(nxt.front());
			nxt.pop();
		}
	}

	cout << ans;
}

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70