Submission #862289

#	Time	Username	Problem	Language	Result	Execution time	Memory
862289		blackslex	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	406 ms	133296 KiB

tracks

#include<bits/stdc++.h>
 
using namespace std;
using pii = pair<int, int>;
 
const int N = 4005, cd[4][2] = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
int n, m, d[N][N], mx = 1;
char c[N][N];
deque<pii> q;
 
int main() {
	scanf("%d %d", &n, &m);
	for (int i = 0; i < n; i++) scanf("%s", c[i]);
	d[0][0] = 1;
	q.emplace_back(0, 0);
	while (!q.empty()) {
		int x, y;
		tie(x, y) = q.front();
		q.pop_front();
		mx = max(mx, d[x][y]);
		for (int i = 0; i < 4; i++) {
			int nx = x + cd[i][0], ny = y + cd[i][1];
			if (nx < 0 || nx >= n || ny < 0 || ny >= m || c[nx][ny] == '.' || d[nx][ny]) continue;
			if (c[nx][ny] == c[x][y]) d[nx][ny] = d[x][y], q.emplace_front(nx, ny);
			else d[nx][ny] = d[x][y] + 1, q.emplace_back(nx, ny);
		}
	}
	printf("%d", mx);
}

Compilation message (stderr)

tracks.cpp: In function 'int main()':
tracks.cpp:12:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |  scanf("%d %d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~
tracks.cpp:13:35: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |  for (int i = 0; i < n; i++) scanf("%s", c[i]);
      |                              ~~~~~^~~~~~~~~~~~

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