Submission #777478

#	Time	Username	Problem	Language	Result	Execution time	Memory
777478		OrazB	Tracks in the Snow (BOI13_tracks)	C++17	86.88 / 100	2086 ms	43080 KiB

tracks

#include <iostream>
#include <vector>
#include <queue>
using namespace std;
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#define pii pair <int, int>
#define ff first
#define ss second
 
int X[] = {-1, 1, 0, 0};
int Y[] = {0, 0, -1, 1};
 
int main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, m;
	cin >> n >> m;
	vector<vector<char>> c(n+1, vector<char>(m+1));
	for (int i = 1; i <= n; i++){
		for (int j = 1; j <= m; j++) cin >> c[i][j];
	}
	int ans = 0;
	vector<vector<bool>> vis(n+1, vector<bool>(m+1, 0));
	priority_queue<pair<int,pii>> q; q.push({-1, {1, 1}});
	vis[1][1] = 1;
	while(!q.empty()){
		int x = q.top().ss.ff, y = q.top().ss.ss, w = q.top().ff;
		q.pop();
		ans = max(ans, -w);
		for (int i = 0; i < 4; i++){
			int a = x+X[i], b = y+Y[i];
			if (a > 0 and b > 0 and a <= n and b <= m and !vis[a][b] and c[a][b] != '.'){
				vis[a][b] = 1;
				if (c[x][y] != c[a][b]) q.push({w-1, {a, b}});
				else q.push({w, {a, b}});
			}
		}
	}
	cout << ans << '\n';
}

Compilation message (stderr)

tracks.cpp:6: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    6 | #pragma GCC optimization ("O3")
      | 
tracks.cpp:7: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    7 | #pragma GCC optimization ("unroll-loops")
      |

• Subtask 1: 30 / 30
• Subtask 2: 56.875 / 70