Submission #447724

#	Time	Username	Problem	Language	Result	Execution time	Memory
447724		Return_0	Kangaroo (CEOI16_kangaroo)	C++17	0 / 100	1 ms	332 KiB

kangaroo

#pragma GCC optimize("Ofast,unroll-loops")
// #pragma comment(linker, "/stack:200000000")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma,tune=native")

#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;

typedef int ll;
typedef long double ld;
typedef pair <ll, ll> pll;

#ifdef SINA
#define dbg(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1> void __f(const char* name, Arg1&& arg1) { cout << name << " : " << arg1 << std::endl; }
template <typename Arg1, typename... Args> void __f (const char* names, Arg1&& arg1, Args&&... args) {
	const char* comma = strchr(names + 1, ',');cout.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...); }
#define dbg2(x, j, n) cout<< #x << " : "; output((j), (n), x, 1); cout.flush();
#else
#define dbg(...) 0
#define dbg2(x, j, n) 0
#endif
#define SZ(x) ((ll)((x).size()))
#define File(s, t) freopen(s ".txt", "r", stdin); freopen(t ".txt", "w", stdout);
#define input(j, n, a) for (int _i = (j); _i < (n)+(j); _i++) cin>> a[_i];
#define output(j, n, a, t) for (int _i = (j); _i < (n)+(j); _i++) cout<< a[_i] << (((t) && _i != (n)+(j)-1)? ' ' : '\n');
#define kill(x) return cout<< (x) << endl, 0
#define cl const ll
#define fr first
#define sc second
#define lc (v << 1)
#define rc (lc | 1)
#define mid ((l + r) >> 1)
#define All(x) (x).begin(), (x).end()

cl inf = sizeof(ll) == 4 ? (1e9 + 10) : (3e18), mod = 1e9 + 7, MOD = 998244353;

template <class A,class B> ostream& operator << (ostream& out,const pair<A,B>&a){return out<<'('<<a.first<<", "<<a.second<<')';}
template <class A> ostream& operator << (ostream& out, const vector<A> &a) {
	out<< '['; for (int i = -1; ++i < int(a.size());) out<< a[i] << (i + 1 < int(a.size()) ? ", " : ""); return out<<']'; }
template <class T, typename _t = less <T> > using Tree = tree <T, null_type, _t, rb_tree_tag, tree_order_statistics_node_update>;

cl N = 1e3 + 7;

mt19937 rng(chrono::steady_clock().now().time_since_epoch().count());
ll par [N], bfs [N], lst, n, m;
vector <ll> adj [N];
vector <pll> E;
bool mark [N];

inline bool in (cl &v, cl &u) {
	auto it = lower_bound(All(adj[v]), u);
	return (it != adj[v].end() && *it == u);
}

void terminate_kon (ll v) {
	for (; v; v = par[v]) cout<< v << ' '; cout<< endl;
	exit(0);
}

int main ()
{
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	cin>> n >> m;
	for (ll v, u, i = 0; i < m; i++) {
		cin>> v >> u;
		E.push_back({v, u});
		adj[v].push_back(u);
		adj[u].push_back(v);
	}

	shuffle(All(E), rng);
	shuffle(All(E), rng);
	for (ll i = 1; i <= n; i++) sort(All(adj[i]));

	for (ll i = 0, v, u; i < m; i++) {
		if ((1000 * clock() / CLOCKS_PER_SEC) > 2900) kill("no");
		memset(mark, 0, sizeof mark);
		v = E[i].fr, u = E[i].sc;
		for (ll j = 1; j <= n; j++) if (in(j, v) && in(j, u)) mark[j] = true;
		par[v] = 0; lst = 0;
		mark[v] = 1;
		for (auto &x : adj[v]) if (!mark[x] && x != u) bfs[lst++] = x, mark[x] = 1, par[x] = v;
		for (ll l = 0; l < lst; l++) {
			v = bfs[l];
			if (v == u) terminate_kon(v);
			for (auto &x : adj[v]) if (!mark[x]) bfs[lst++] = x, mark[x] = 1, par[x] = v;
		}
	}

	cout<< "no";

	cerr<< "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";

	return 0;
}
/*
5 6
1 2
1 3
2 3
4 3
5 2
4 5

4 5
1 2
2 3
3 4
4 1
1 3

*/

Compilation message (stderr)

kangaroo.cpp: In function 'void terminate_kon(ll)':
kangaroo.cpp:60:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   60 |  for (; v; v = par[v]) cout<< v << ' '; cout<< endl;
      |  ^~~
kangaroo.cpp:60:41: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   60 |  for (; v; v = par[v]) cout<< v << ' '; cout<< endl;
      |                                         ^~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 30
• Subtask 3: 0 / 15
• Subtask 4: 0 / 49