Submission #405233

#	Time	Username	Problem	Language	Result	Execution time	Memory
405233		rieyuw	Tracks in the Snow (BOI13_tracks)	C++14	100 / 100	752 ms	122748 KiB

tracks

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <stack>
#include <unordered_set>
#include <set>
#include <map>
#include <unordered_map>
#include <iomanip>
#include <random>
#include <queue>
//#include <fstream>
/*#include <cstdio>
#include <ctime>*/
#include <complex>

using namespace std;

/*Problem:  */

void solve()
{
	
	int n, m;
	cin >> n >> m;
	vector<vector<char>> grid(n, vector<char>(m));
	vector <vector<int>> depth(n, vector<int>(m));
	for (int i = 0; i < n; i++)
		for (int j = 0; j < m; j++)
			cin >> grid[i][j];
	

	/*cout << "grid" << endl;
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < m; j++)
			cout << grid[i][j];
		cout << endl;
	}*/


	int x[] = {-1, 1, 0, 0 };
	int y[] = { 0, 0, -1, 1 };

	deque<pair<int, int>> deck;
	deck.push_front({ 0, 0 });
	depth[0][0] = 1;


	pair<int, int> trace, neig;
	char ani; int ani_depth;
	int ans = -1;
	while (!deck.empty())
	{
		trace = deck.front(); deck.pop_front();
		ani = grid[trace.first][trace.second];
		ani_depth = depth[trace.first][trace.second];

		ans = max(ans, ani_depth);

		for (int i = 0; i < 4; i++)
		{
			neig.first = trace.first + x[i];
			neig.second = trace.second + y[i];
			if (neig.first < 0 || neig.first >= n
				|| neig.second < 0 || neig.second >= m
				|| depth[neig.first][neig.second] != 0
				|| grid[neig.first][neig.second] == '.')
				continue;

			if (grid[neig.first][neig.second] == ani)
			{
				depth[neig.first][neig.second] = ani_depth;
				deck.push_front(neig);
			}
			else
			{
				depth[neig.first][neig.second] = ani_depth + 1;
				deck.push_back(neig);
			}
		}
	}

	/*cout << "depths" << endl;
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < m; j++)
			cout << depth[i][j];
		cout << endl;
	}
	*/



	cout << ans << endl;
}

int main() {
	//freopen("revegetate.in", "r", stdin);
	//freopen("revegetate.out", "w", stdout);
	cin.tie(0);
	ios::sync_with_stdio(0);

	int t = 1;
	//cin >> t;

	while (t--)
		solve();


	return 0;
}

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