Submission #830083

#	Time	Username	Problem	Language	Result	Execution time	Memory
830083		NK_	Rigged Roads (NOI19_riggedroads)	C++17	0 / 100	244 ms	262144 KiB

riggedroads

// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>

using namespace std;
 
#define nl '\n'
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define sz(x) int(x.size())
 
template<class T> using V = vector<T>;
using vi = V<int>;
using ll = long long;
using pi = pair<int, int>;
using vpi = V<pi>;
using vl = V<ll>;
using db = long double;

const int INF = 1e9 + 10;

struct DSU {
	vi e; void init(int N) { e = vi(N, -1); }
	int get(int x) { return e[x] < 0 ? x : e[x] = get(e[x]); }
	void unite(int x, int y) {
		x = get(x), y = get(y);
		e[x] += e[y]; e[y] = x;
	}
};


int main() {
	cin.tie(0)->sync_with_stdio(0);
	
	int N, M; cin >> N >> M;

	vpi E;
	for(int i = 0; i < M; i++) {
		int u, v; cin >> u >> v; --u, --v;
		E.pb(mp(u, v));
	}

	V<vpi> adj(N); vi on(M);
	for(int i = 0; i < N - 1; i++) {
		int x; cin >> x; --x;
		on[x] = 1;
		auto [u, v] = E[x];
		adj[u].pb(mp(v, x));
		adj[v].pb(mp(u, x));
	}

	vi par(N), id(N), dep(N);
	function<void(int)> dfs = [&](int u) {
		for(auto& e : adj[u]) if (e.f != par[u]) {
			id[e.f] = e.s; dep[e.f] = dep[u] + 1; par[e.f] = u; dfs(e.f);
		}
	};

	par[0] = -1, id[0] = -1, dep[0] = 0; dfs(0);

	vi ans(M, -1); int cur = 1; DSU D; D.init(N);
	for(int i = 0; i < M; i++) {
		auto [u, v] = E[i];
		if (on[i]) {
			if (dep[u] > dep[v]) swap(u, v);
			assert(par[v] == u && id[v] == i);
			
			D.unite(u, v); ans[i] = cur++;
			continue;
		}


		vi upd;
		while(1) {
			int a = D.get(u), b = D.get(v);
			if (a == b) break;
			if (dep[a] < dep[b]) swap(a, b);
			assert(par[a] != -1);
			D.unite(par[a], a);
			upd.pb(id[a]);
		}

		sort(begin(upd), end(upd));

		for(auto x : upd) ans[x] = cur++;
		ans[i] = cur++;
	}

	for(auto x : ans) cout << x << " ";
	cout << nl;

    return 0;
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 19
• Subtask 3: 0 / 9
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 12
• Subtask 7: 0 / 32