제출 #60074

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
60074		aome	낙하산 고리들 (IOI12_rings)	C++17	0 / 100	1307 ms	69084 KiB

rings

#include <bits/stdc++.h>

using namespace std;

const int N = 1000005;

int n;
int par[N];
int deg[N];
int visit[N];
int root = -1;
bool inCircle[N];
bool noSolution;
bool checkConnect;
vector<int> G[N];
vector<int> vnode;
vector<int> vcircle;

int find(int u) { return u == par[u] ? u : par[u] = find(par[u]); }

bool join(int u, int v) { u = find(u), v = find(v), par[u] = v; return u != v; }

void Init(int _n) {
	n = _n;
	for (int i = 0; i < n; ++i) par[i] = i;
}

vector<int> findPath(int A, int B) {
	for (int i = 0; i < n; ++i) visit[i] = -1;
	queue<int> qu; visit[A] = A, qu.push(A);
	while (qu.size()) {
		int u = qu.front(); qu.pop();
		for (auto v : G[u]) {
			if (visit[v] == -1) visit[v] = u, qu.push(v);
		}
	}
	vector<int> path;
	int cur = B;
	while (cur != A) {
		path.push_back(cur), cur = visit[cur];
	}
	path.push_back(A);
	return path;
}

void Link(int A, int B) {
	if (noSolution) return;
	if (!join(A, B)) {
		if (root != -1) {
			if (find(root) != find(A)) {
				noSolution = 1; return;
			}
		}
		else {
			root = A;
			vcircle = findPath(A, B);
			for (auto i : vcircle) inCircle[i] = 1;
		}
	}
	deg[A]++, deg[B]++;
	G[A].push_back(B), G[B].push_back(A);
	if (deg[A] == 3) vnode.push_back(A);
	if (deg[B] == 3) vnode.push_back(B);
	if (vnode.size() == 3) {
		noSolution = 1; return;
	}
	if (vnode.size() == 2) {
		if (deg[vnode[0]] != 3 || deg[vnode[1]] != 3) {
			noSolution = 1; return;
		}
		if (checkConnect) return;
		checkConnect = 1;
		bool found = 0;
		for (auto v : G[vnode[0]]) {
			found |= v == vnode[1];
		}
		if (!found) {
			noSolution = 1; return;
		}
	}
}

int CountCritical() {
	if (noSolution) return 0;
	if (!vnode.size()) {
		if (root != -1) return vcircle.size();
		else return n;
	}
	if (vnode.size() == 1) {
		if (root != -1 && !inCircle[vnode[0]]) {
			noSolution = 1; return 0;
		}
		if (deg[vnode[0]] > 3) return 1;
		if (root != -1) return 3;
		return 4;
	}
	if (root != -1 && (!inCircle[vnode[0]] || !inCircle[vnode[1]])) {
		noSolution = 1; return 0;
	}
	return 2;
}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 17
• Subtask 3: 0 / 18
• Subtask 4: 0 / 14
• Subtask 5: 0 / 31