Submission #888471

#	Time	Username	Problem	Language	Result	Execution time	Memory
888471		bashNewbie	Tracks in the Snow (BOI13_tracks)	C++17	75.83 / 100	1031 ms	140720 KiB

tracks

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <queue>
using namespace std;

#define fast_io ios::sync_with_stdio(0), cin.tie(0)
#define vi vector<int>
#define vvi vector<vi>
#define vs vector<string>
#define pb push_back

int main() {
	fast_io;

	int n, m; cin >> n >> m;
	vs s(n); for(auto &t: s) cin >> t;

	auto in = [&] (int x) {
		return -1 < x && x < n*m;
	};
	auto bad = [&] (int x) {
		return s[x/m][x%m] == '.';
	};
	auto same = [&] (int x, int y) {
		int xr = x/m, xc = x%m, yr = y/m, yc = y%m;
		return s[xr][xc] == s[yr][yc];
	};

	queue<int> q, nq; vi vis(n*m), adj = {-m, -1, 1, m}; int ret = 0;
	q.push(0), vis[0] = 1;
	while(!q.empty()) {
		ret++;
		while(!q.empty()) {
			int x = q.front(); q.pop(), nq.push(x);
			for(int c: adj) {
				int y = x+c;
				if(!in(y) || vis[y] || bad(y) || !same(x, y)) continue;
				q.push(y), vis[y] = 1;
			}
		}
		while(!nq.empty()) {
			int x = nq.front(); nq.pop();
			for(int c: adj) {
				int y = x+c;
				if(!in(y) || vis[y] || bad(y)) continue;
				q.push(y), vis[y] = 1;
			}
		}
	}
	cout << ret << "\n";
}

• Subtask 1: 23.333333333333332 / 30
• Subtask 2: 52.5 / 70