Submission #46375

#	Time	Username	Problem	Language	Result	Execution time	Memory
46375		RockyB	One-Way Streets (CEOI17_oneway)	C++17	30 / 100	3029 ms	26456 KiB

oneway

/// In The Name Of God

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include <bits/stdc++.h>

#define f first
#define s second

#define pb push_back
#define pp pop_back
#define mp make_pair

#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()

#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);

#define nl '\n'
#define ioi exit(0);

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

const int N = (int)3e5 + 7;
const int inf = (int)1e9 + 7;
const int mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;

const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1};
const int dy[] = {0, 1, 0, -1, 1, -1, 1, -1};

using namespace std;

int n, m, k;
int v[N], u[N], x[N], y[N];
multiset <int> g[N];

int tmr;
int was[N], ans[N];

bool check() {
	for (int i = 1; i <= k; i++) {
		++tmr;
		was[x[i]] = tmr;
		bool ok = 0;
		queue <int> q;
		q.push(x[i]);
		while (sz(q)) {
			int v = q.front();
			if (v == y[i]) {
				ok = 1;
				break;
			}
			q.pop();
			for (auto to : g[v]) {
				if (was[to] != tmr) {
					was[to] = tmr;
					q.push(to);
				}
			}
		}
		if (!ok) return 0;
	}
	return 1;
}
int main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
	#endif
	Kazakhstan
	cin >> n >> m;
	for (int i = 1; i <= m; i++) {
		cin >> v[i] >> u[i];
		g[v[i]].insert(u[i]);
		g[u[i]].insert(v[i]);
	}
	cin >> k;
	for (int i = 1; i <= k; i++) {
		cin >> x[i] >> y[i];
	}
	for (int i = 1; i <= m; i++) {
		g[u[i]].erase(g[u[i]].find(v[i]));
		if (check()) ans[i] = 1;
		g[u[i]].insert(v[i]);
		g[v[i]].erase(g[v[i]].find(u[i]));
		if (check()) {
			if (ans[i] == 1) ans[i] = 3;
			else ans[i] = 2;
		}
		g[v[i]].insert(u[i]);
		if (ans[i] == 1) g[u[i]].erase(g[u[i]].find(v[i]));
		else if (ans[i] == 2) g[v[i]].erase(g[v[i]].find(u[i]));
	}

	for (int i = 1; i <= m; i++) {
		if (ans[i] == 3) cout << 'B';
		else if (ans[i] == 1) cout << 'R';
		else cout << 'L';
	}
	ioi
}

• Subtask 1: 30 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40