Submission #257606

#	Time	Username	Problem	Language	Result	Execution time	Memory
257606		super_j6	Potemkin cycle (CEOI15_indcyc)	C++14	10 / 100	138 ms	48632 KiB

indcyc

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
#define endl '\n'
#define ll long long
#define pi pair<int, int>
#define f first
#define s second

const int mxn = 1000, mxm = 100000;
int n, m;
int u[mxm], v[mxm], vis[mxm], p[mxm];
bool a[mxn][mxn];
vector<int> g[mxn], gr[mxm];

void dfs(int c){
	vis[c] = 1;
	for(int i : gr[c]){
		if(!vis[i]){
			p[i] = c;
			dfs(i);
		}else if(i != p[c]){
			for(int j = 0; j < 2; j++){
				for(int l = 0; l < 2; l++){
					if(u[c] == v[i]) goto hell;
					swap(u[i], v[i]);
				}
				swap(u[c], v[c]);
			}
			hell:
			cout << u[i] + 1;
			for(int j = c; ~j && u[j] != u[i]; j = p[j]){
				cout << " " << u[j] + 1;
				if(~p[j] && u[p[j]] != v[j]) swap(u[p[j]], v[p[j]]);
			}
			cout << endl;
			exit(0);
		}
	}
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> m;
	
	for(int i = 0; i < m; i++){
		cin >> u[i] >> v[i];
		u[i]--, v[i]--;
		a[u[i]][v[i]] = a[v[i]][u[i]] = 1;
		g[u[i]].push_back(i);
		g[v[i]].push_back(i);
	}
	
	for(int i = 0; i < n; i++)
	for(int j = 0; j < g[i].size(); j++)
	for(int l = 0; l < j; l++){
		int x = g[i][j], y = g[i][l];
		if(!a[i ^ u[x] ^ v[x]][i ^ u[y] ^ v[y]]){
			gr[x].push_back(y);
			gr[y].push_back(x);	
		} 
	}
	
	for(int c = 0; c < m; c++)
	for(int i : gr[c]){
		for(int j = 0; j < 2; j++){
			for(int l = 0; l < 2; l++){
				if(u[c] == v[i]) goto hell;
				swap(u[i], v[i]);
			}
			swap(u[c], v[c]);
		}
		hell:
		while(u[c] != v[i]) cout << 'f' << endl;
	}
	
	
	p[0] = -1;
	dfs(0);
	
	cout << "no" << endl;

	return 0;
}

Compilation message (stderr)

indcyc.cpp: In function 'int main()':
indcyc.cpp:60:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int j = 0; j < g[i].size(); j++)
                 ~~^~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10