Submission #888478

#	Time	Username	Problem	Language	Result	Execution time	Memory
888478		bashNewbie	Tracks in the Snow (BOI13_tracks)	C++17	82.50 / 100	2136 ms	687312 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 n, m;
vs s;

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

int main() {
	fast_io;

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

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

	queue<vi> q, nq; vi vis(n*m); int ret = 0;
	vi src = {0, 0};
	q.push(src), vis[g(src)] = 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: 52.5 / 70