Submission #1247839

#	Time	Username	Problem	Language	Result	Execution time	Memory
1247839		menkh	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	976 ms	119052 KiB

tracks

#include <bits/stdc++.h>
using namespace std;

#define ll long long
int dx[4] = {1, -1, 0, 0}; 
int dy[4] = {0, 0, 1, -1};

int n, m, depth[4000][4000], answer = 1;
char snow[4000][4000];

bool inside(int x, int y) {
	return (x > -1 && x < n && y > -1 && y < m && snow[x][y] != '.');
}

void solve() {
    scanf("%d %d", &n, &m);
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) scanf(" %c", &snow[i][j]);
    }

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

    while (!q.empty()) {
		pair<int, int> c = q.front();
		q.pop_front();
		answer = max(answer, depth[c.first][c.second]);

		for (int i = 0; i < 4; i++) {
			int x = c.first + dx[i], y = c.second + dy[i];
			if (inside(x, y) && depth[x][y] == 0) {
				if (snow[x][y] == snow[c.first][c.second]) {
					depth[x][y] = depth[c.first][c.second];
					q.push_front({x, y});
				} else {
					depth[x][y] = depth[c.first][c.second] + 1;
					q.push_back({x, y});
				}
			}
		}
	}

    printf("%d", answer);
}

int main() {
    solve();
}

Compilation message (stderr)

tracks.cpp: In function 'void solve()':
tracks.cpp:16:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
tracks.cpp:18:42: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |         for (int j = 0; j < m; j++) scanf(" %c", &snow[i][j]);
      |                                     ~~~~~^~~~~~~~~~~~~~~~~~~~

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