제출 #343892

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
343892		kapsel	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	707 ms	130812 KiB

tracks

#include <bits/stdc++.h>

using namespace std;

/*
 * BFS 0/1
 * Dla krawedzi o wagach 0 lub 1.
 * Zadanie: BOI 2013 Tracks in the Snow: https://oj.uz/problem/view/BOI13_tracks
 */

#define LL long long
#define ULL unsigned LL
#define LD long double

const int N = 4e3 + 4;
int dx[4]{1, -1, 0, 0}, dy[4]{0, 0, 1, -1};
int n, m, depth[N][N];
string snow[N];

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

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin>>n>>m;
	for(int i=0; i<n; i++)
		cin>>snow[i];
	deque<pair<int, int>> q;
	q.push_back({0, 0});
	depth[0][0] = 1;
	int ans = 1;
	while(q.size()) {
		pair<int, int> c = q.front();
		q.pop_front();
		ans = max(ans, 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});
				}
			}
		}
	}
	cout<<ans;
}

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