Submission #119229

#	Time	Username	Problem	Language	Result	Execution time	Memory
119229		ioilolcom	Parachute rings (IOI12_rings)	C++14	20 / 100	4086 ms	104196 KiB

rings

#include <bits/stdc++.h>
using namespace std;
#define endl "\n"
#define pii pair<int,int>
#define x first
#define y second
typedef long long int ll;
int N;
const int M=1e6+7;
set<int> adj[M];
int parent[M];
struct DSU {
	DSU(int n){
		for(int i=0; i<N; i++) parent[i] = i;
	}
	inline int find(int a){
		if(parent[a] != a) parent[a] = find(parent[a]);
		return parent[a];
	}
	inline void merge(int a,int b){
		int pa = find(a);
		int pb = find(b);
		parent[pa] = pb;
	}
};
void Init(int N_) {
	N = N_;
}
vector<pii> edges;
void Link(int A, int B) {
	adj[A].insert(B);
	adj[B].insert(A);
	edges.push_back({A,B});
}
bool is(int l){
	DSU dsu(N);
	int deg[N+1];
	for(int i=0; i<N; i++) {
		deg[i]=0;
	}
	for(auto m:edges) {
		if(m.x==l||m.y==l) {
			continue;
		}
		if(dsu.find(m.x)==dsu.find(m.y)) {
			return 0;
		}
		dsu.merge(m.x,m.y);
		deg[m.x]++;
		deg[m.y]++;
	}
	for(int i=0; i<N; i++) {
		if(deg[i]>2) {
			return 0;
		}
	}
	return 1;
}
int CountCritical() {
	int ans=0;
	for(int x=0; x<N; x++) ans+=is(x);
	return ans;
}

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