Submission #338705

#	Time	Username	Problem	Language	Result	Execution time	Memory
338705		ryansee	Village (BOI20_village)	C++14	100 / 100	194 ms	96176 KiB

Village

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

#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());    //can be used by calling rng() or shuffle(A, A+n, rng)
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusivesss
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }

using ll=long long; 
using ld=long double;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,pi>; 

long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (100006)
ll n;
vector<int> v[MAXN];
pair<ll, vector<ll>> solve1() {
	ll ans = 0;
	vector<ll> A(n+1, -1), at(n+1, 0);
	FOR(i,1,n)at[i]=i;
	function<void(ll,ll)>dfs=[&](ll x,ll p) {
		for(auto i:v[x]) if(i^p) {
			dfs(i, x);
			if(at[i] == i) {
				swap(at[i], at[x]), ans += 2;
			}
		}
	};
	dfs(1,1);
	if(at[1]==1) for(auto i:v[1]) { ans+=2, swap(at[1],at[i]); break; }
	FOR(i,1,n)A[at[i]]=i;
	A.erase(A.begin());
	return {ans, A};
}
deque<int> *ppl[MAXN];
pair<ll, vector<ll>> solve2() {
	ll ans = 0;
	vector<ll> A(n+1), at(n+1);
	FOR(i,1,n) at[i] = i;
	auto match=[&](ll x,ll y){
		swap(at[x], at[y]);
	};
	function<ll(ll,ll)>dfs=[&](ll x,ll p){
		ll sz = 1;
		for(auto i:v[x]) if(i^p) {
			sz += dfs(i, x);
		}
		ppl[x] = new deque<int>;
		for(auto i:v[x]) if(i^p) {
			if(ppl[x]->size() < ppl[i]->size()) ppl[x] = ppl[i];
		}
		for(auto i:v[x]) if(i^p&&ppl[x]!=ppl[i]) {
			for(auto j:*ppl[i]) {
				match(ppl[x]->front(), j);
				ppl[x]->eb(ppl[x]->front());
				ppl[x]->pop_front();
				ppl[x]->eb(j);
			}
		}
		ans += ppl[x]->size() * 2;
		if(ppl[x]->size()){
			match(ppl[x]->front(), x);
			ppl[x]->eb(ppl[x]->front());
			ppl[x]->pop_front();
		}
		ppl[x]->eb(x);
		while(ppl[x]->size() > (n-sz)) ppl[x]->pop_back();
		return sz;
	};
	dfs(1,1);
	FOR(i,1,n) A[at[i]]=i;
	A.erase(A.begin());
	return {ans, A};
}
int main() {
	FAST
	cin>>n;
	FOR(i,2,n){
		ll a,b;
		cin>>a>>b;
		v[a].eb(b), v[b].eb(a);
	}
	auto mi = solve1();
	auto mx = solve2();
	cout<<mi.f<<' '<<mx.f<<'\n';
	for(auto i:mi.s) cout<<i<<' '; cout<<'\n';
	for(auto i:mx.s) cout<<i<<' '; cout<<'\n';
}

Compilation message (stderr)

Village.cpp: In lambda function:
Village.cpp:81:24: warning: comparison of integer expressions of different signedness: 'std::deque<int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   81 |   while(ppl[x]->size() > (n-sz)) ppl[x]->pop_back();
      |         ~~~~~~~~~~~~~~~^~~~~~~~
Village.cpp: In function 'int main()':
Village.cpp:100:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  100 |  for(auto i:mi.s) cout<<i<<' '; cout<<'\n';
      |  ^~~
Village.cpp:100:33: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  100 |  for(auto i:mi.s) cout<<i<<' '; cout<<'\n';
      |                                 ^~~~
Village.cpp:101:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  101 |  for(auto i:mx.s) cout<<i<<' '; cout<<'\n';
      |  ^~~
Village.cpp:101:33: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  101 |  for(auto i:mx.s) cout<<i<<' '; cout<<'\n';
      |                                 ^~~~

• Subtask 1: 12 / 12
• Subtask 2: 38 / 38
• Subtask 3: 50 / 50