제출 #348411

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
348411		dennisstar	Parachute rings (IOI12_rings)	C++17	100 / 100	2230 ms	111620 KiB

rings

#include <bits/stdc++.h>
using namespace std;

const int MX = 1e6 + 5;

int N, deg[MX], cy, fl;
int dd[4][MX], p[4][MX], chk[4];
vector<int> adj[MX];

int pr[MX], sz[MX];
int gp(int a) { return pr[a]?(pr[a]=gp(pr[a])):a; }
bool un(int a, int b) {
	a=gp(a), b=gp(b);
	if (a!=b) {
		pr[b]=a;
		sz[a]+=sz[b];
	}
	return a!=b;
}

int gp(int a, int *p) { return p[a]?(p[a]=gp(p[a], p)):a; }
bool un(int a, int b, int *p) {
	a=gp(a, p), b=gp(b, p);
	if (a!=b) p[b]=a;
	return a!=b;
}

vector<int> al;
void add(int u, int v) {
	for (int t=0; t<al.size(); t++) {
		int i=al[t];
		if (i==u||i==v) continue;
		if (!un(u, v, p[t])) chk[t]=0;
		dd[t][u]++, dd[t][v]++;
		if (dd[t][u]>=3||dd[t][v]>=3) chk[t]=0;
	}
}
void init(int x) {
	al.emplace_back(x);
	for (auto &i:adj[x]) al.emplace_back(i);
	for (int i=0; i<al.size(); i++) chk[i]=1;
	for (int i=1; i<=N; i++) for (auto &j:adj[i]) if (i<j) add(i, j);
}

void Init(int N) {
	::N=N;
	fill(sz, sz+N+1, 1);
}

void Link(int a, int b) {
	a++; b++;
	deg[a]++; deg[b]++;
	adj[a].emplace_back(b);
	adj[b].emplace_back(a);
	if (!fl&&deg[a]==3) fl=1, init(a);
	else if (!fl&&deg[b]==3) fl=1, init(b);
	else if (!fl) {
		if (!un(a, b)) {
			if (cy) cy=-1;
			else cy=gp(a);
		}
	}
	else add(a, b);
}

int CountCritical() {
	if (cy==-1) return 0;
	else if (!fl) return cy?sz[cy]:N;
	else {
		int c=0;
		for (int i=0; i<al.size(); i++) c+=chk[i];
		return c;
	}
}

컴파일 시 표준 에러 (stderr) 메시지

rings.cpp: In function 'void add(int, int)':
rings.cpp:30:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |  for (int t=0; t<al.size(); t++) {
      |                ~^~~~~~~~~~
rings.cpp: In function 'void init(int)':
rings.cpp:41:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |  for (int i=0; i<al.size(); i++) chk[i]=1;
      |                ~^~~~~~~~~~
rings.cpp: In function 'int CountCritical()':
rings.cpp:71:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |   for (int i=0; i<al.size(); i++) c+=chk[i];
      |                 ~^~~~~~~~~~

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