Submission #888477

#	Time	Username	Problem	Language	Result	Execution time	Memory
888477		bashNewbie	Tracks in the Snow (BOI13_tracks)	C++17	69.38 / 100	2075 ms	344556 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;

	vvi adj = {{-1, 0}, {0, -1}, {1, 0}, {0, 1}};

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

	auto in = [&] (vi v) {
		return -1 < v[0] && v[0] < n && -1 < v[1] && v[1] < m;
	};
	auto f = [&] (vi v) {
		return s[v[0]][v[1]];
	};
	auto g = [&] (vi v) {
		return v[0]*m+v[1];
	};
	auto bad = [&] (vi v) {
		return f(v) == '.';
	};
	auto same = [&] (vi v, vi w) {
		return f(v) == f(w);
	};

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

• Subtask 1: 30 / 30
• Subtask 2: 39.375 / 70