Submission #24149

#	Time	Username	Problem	Language	Result	Execution time	Memory
24149		Hiasat	Parachute rings (IOI12_rings)	C++14	0 / 100	2365 ms	118504 KiB

rings

#include <bits/stdc++.h>

using namespace std;
const int MX = 1000001;

const int CHAIN = 0;
const int CYCLE = 1;
const int THREE = 2;
const int BIG = 3;
const int BLOCKED = 4;

int dsu[1000001],last[10], E[1000001], freq[1000001][5], sz[1000001], in[1000001], big[1000001][5], vis[1000001], type[1000001], pre[1000001], vsId, N;
vector<int> adj[1000001];
bool block[1000001];

int res = 0,ff2[10];
bool ZERO = 0;

int find(int u) {
	return dsu[u] == u ? u : dsu[u] = find(dsu[u]);
}
void Init(int N_) {
	N = N_;
	for (int i = 0; i < N; ++i) {
		dsu[i] = i;
		freq[i][0] = 1;
		pre[i] = 1;
		res += pre[i];
		E[i] = 0;
		sz[i] = 1;
		ff2[0]++;
	}
}
bool fn(int u, int p) {
	if (vis[u] == vsId) {
		return false;
	}
	if (!block[u] && in[u] > 2)
		return false;
	vis[u] = vsId;
	for (int i = 0; i < adj[u].size(); ++i) {
		int v = adj[u][i];
		if (v == p || block[v])
			continue;
		if (block[u] && vis[v] == vsId)
			continue;
		if (!fn(v, u))
			return false;
	}
	return true;
}

bool check(int u , int p) {
	block[u] = 1;
	vsId++;
	for (int i = 0; i < adj[u].size(); ++i) {
		in[adj[u][i]]--;
	}
	bool res = fn(u, p);
	for (int i = 0; i < adj[u].size(); ++i) {
		in[adj[u][i]]++;
	}
	block[u] = 0;
	return res;
}

void Link(int A, int B) {
	if (ZERO)
		return;
	adj[A].push_back(B);
	adj[B].push_back(A);
	if (type[find(A)] == BLOCKED || type[find(B)] == BLOCKED)
		return;
	if (find(A) == find(B) && (B == big[find(A)][4] || A == big[find(B)][4]))
		return;
	freq[find(A)][in[A]]--;
	freq[find(B)][in[B]]--;
	in[A]++, in[B]++;
	in[A] = min(in[A], 4);
	in[B] = min(in[B], 4);
	freq[find(A)][in[A]]++;
	freq[find(B)][in[B]]++;
	res -= pre[find(A)];
	ff2[type[find(A)]]--;
	if (find(A) != find(B)) {
		ff2[type[find(B)]]--;
		res -= pre[find(B)];
		for (int i = 0 ; i <= 4  ; i++) {
			if (in[A] == i) {
				big[find(A)][i] = A;
			}
			if (in[B] == i) {
				big[find(B)][i] = B;
			}
		}
		E[find(B)] += E[find(A)];
		sz[find(B)] += sz[find(A)];
		for (int i = 0; i <= 4; ++i) {
			big[find(B)][i] = max(big[find(B)][i], big[find(A)][i]);
			freq[find(B)][i] += freq[find(A)][i];
		}
		dsu[find(A)] = find(B);
	}
	E[find(B)]++;
	if (freq[find(A)][4] > 1 || freq[find(A)][3] > 4) {
		type[find(A)] = BLOCKED;
		ZERO = 1;
	} else if (freq[find(A)][4]) {
		type[find(A)] = BIG;
		pre[find(A)] = 0;
		if (check(big[find(A)][4], -1)) {
			pre[find(A)]++;
		}
		res += pre[find(A)];
	} else if (freq[find(A)][3]) {
		type[find(A)]= THREE;
		pre[find(A)] = 0;
		if(check(big[find(A)][3],-1))
			pre[find(A)]++;
		for (int j = 0 ; j < adj[big[find(A)][3]].size(); j++) {
			int v = adj[big[find(A)][3]][j];
			if (check(v, -1)) {
				pre[find(A)]++;
			}
		}
		res += pre[find(A)];
	} else {
		if (freq[find(A)][2] == sz[find(A)]) {
			type[find(A)] = CYCLE;
		}
		pre[find(A)] = sz[find(A)];
		res += pre[find(A)];
	}
	ff2[type[find(A)]]++;
	last[type[find(A)]] = find(A);
}

int CountCritical() {
	if (ZERO)
		return 0;
	int fn = 0;
	for (int i = 1; i <= 3; ++i){
		fn += type[i];
	}
	if(fn > 1)
		return 0;
	for (int i = 1; i <= 3; ++i){
		if(ff2[i]){
			return pre[last[i]];
		}
	}
	return res;
}

Compilation message (stderr)

rings.cpp: In function 'bool fn(int, int)':
rings.cpp:41:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < adj[u].size(); ++i) {
                  ~~^~~~~~~~~~~~~~~
rings.cpp: In function 'bool check(int, int)':
rings.cpp:56:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < adj[u].size(); ++i) {
                  ~~^~~~~~~~~~~~~~~
rings.cpp:60:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < adj[u].size(); ++i) {
                  ~~^~~~~~~~~~~~~~~
rings.cpp: In function 'void Link(int, int)':
rings.cpp:120:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = 0 ; j < adj[big[find(A)][3]].size(); j++) {
                    ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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