Submission #527206

#	Time	Username	Problem	Language	Result	Execution time	Memory
527206		zaneyu	Potemkin cycle (CEOI15_indcyc)	C++14	100 / 100	901 ms	1568 KiB

indcyc

/*input
5 6
1 2
1 3
2 3
4 3
5 2
4 5
*/ 
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
 
//#pragma GCC optimize("unroll-loops,no-stack-protector")
//order_of_key #of elements less than x
// find_by_order kth element
using ll = long long;
using ld = long double;
using pii = pair<ll,ll>;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
#define f first
#define s second
#define pb push_back
#define REP(i,n) for(int i=0;i<n;i++)
#define REP1(i,n) for(int i=1;i<=n;i++)
#define FILL(n,x) memset(n,x,sizeof(n))
#define ALL(_a) _a.begin(),_a.end()
#define sz(x) (int)x.size()
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#define MP make_pair
const ll INF64=4e17;
const int INF=0x3f3f3f3f;
const ll MOD=1e6+7;
const ld PI=acos(-1);
const ld eps=1e-9;
#define lowb(x) x&(-x)
#define MNTO(x,y) x=min(x,(__typeof__(x))y)
#define MXTO(x,y) x=max(x,(__typeof__(x))y)
template<typename T1,typename T2>
ostream& operator<<(ostream& out,pair<T1,T2> P){
    out<<P.f<<' '<<P.s;
    return out;
}
template<typename T>
ostream& operator<<(ostream& out,vector<T> V){
    REP(i,sz(V)) out<<V[i]+1<<((i!=sz(V)-1)?" ":"");
    return out;
}
ll mult(ll a,ll b){
    return ((a%MOD)*(b%MOD))%MOD;
}
ll mypow(ll a,ll b){
    if(b<=0) return 1;
    ll res=1LL;
    while(b){
        if(b&1) res=mult(res,a);
        a=mult(a,a);
        b>>=1;
    }
    return res;
}
const int maxn=1e4+5;
int dist[maxn],pv[maxn];
vector<int> v[maxn];
bool ad[maxn],ad2[maxn];
mt19937 rng(69);
int main(){
	ios::sync_with_stdio(false),cin.tie(0);
	int n,m;
	cin>>n>>m;
	time_t st=clock();
	REP(i,m){
		int a,b;
		cin>>a>>b;
		--a,--b;
		v[a].pb(b),v[b].pb(a);
	}
	vector<int> vvv;
	REP(i,n) vvv.pb(i);
	if(rng()%3){
		REP(i,n) shuffle(ALL(v[i]),rng);
		shuffle(ALL(vvv),rng);
	}
	REP(i,n) dist[i]=INF;
	for(int i:vvv){
		for(int x:v[i]) ad[x]=1;
		for(int x:v[i]){
			for(int z:v[x]) ad2[z]=1;
			for(int y:v[i]){
				if(x==y or ad2[y]) continue;
				ad[y]=0;
				queue<int> q;
				q.push(x);
				dist[x]=0;
				vector<int> vv={x};
				while(sz(q)){
					int z=q.front();
					q.pop();
					if(z==y) break;
					vv.pb(z);
					for(int x:v[z]){
						if(x==i or ad[x]) continue;
						if(dist[x]>dist[z]+1){
							dist[x]=dist[z]+1;
							pv[x]=z;
							q.push(x);
						}
					}
				}
				if(dist[y]!=INF){
					while(y!=x){
						cout<<y+1<<' ';
						y=pv[y];
					}
					cout<<x+1<<' '<<i+1<<'\n';
					return 0;
				}
				for(int z:vv) dist[z]=INF;
				if(clock()-st>=(900000)){
					cout<<"no";
					return 0;
				}
				ad[y]=1;
			}
			for(int z:v[x]) ad2[z]=0;
		}
		for(int x:v[i]) ad[x]=0;
	}
	cout<<"no";
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10