Submission #236585

#	Time	Username	Problem	Language	Result	Execution time	Memory
236585		MvC	Meetings (JOI19_meetings)	C++14	100 / 100	1946 ms	1028 KiB

meetings

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#include "meetings.h"
#define fr first
#define sc second
#define vec vector
#define pb push_back
#define pii pair<int, int>
#define forn(x,y) for(int x = 1 ; x <= (int)y ; ++x)
#define all(x) (x).begin(),(x).end()
#define fast cin.tie(0);cout.tie(0);cin.sync_with_stdio(0);cout.sync_with_stdio(0);
 
using namespace std;
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
 
typedef long long ll;
typedef unsigned int uint;
typedef complex<int> point;
const int nmax = 100005;
const ll linf = 1e18;
const ll mod = 998244353;
const int inf = INT_MAX;
 
vec < pii > eds;
 
int find_center(vec <int> &asd){
	if(asd.size() <= 10)return asd[0];
	vec<int> cnt(asd.size());
	int tries = asd.size()/10;
	srand(time(0));
	while(tries --){
		int m = asd.size();
		int a, b, c;
		a = asd[rand()%m];
		b = asd[rand()%m];
		while(b == a) b = asd[rand()%m];
		c = asd[rand()%m];
		while(c == b || c == a)c = asd[rand()%m];
		// a,b,c - random din asd
		int p = Query(a,b,c);
		cnt[ lower_bound(all(asd),p) - asd.begin()]++;
	}
	int mx = 0;
	for(int i = 0; i < cnt.size() ; i++){
		if(cnt[mx] < cnt[i])mx = i;
	}
	cnt.clear();
	return asd[mx];
}
void solves(vec <int> &tb){
	if(tb.size() == 1)return ;
	int A = find_center(tb);
	int B = tb[0];
	if(B == A)B = tb[1];
	for(int i : tb){
		if(i != A && i != B && Query(A,B,i) == i) B = i;
	}
	eds.pb({A,B});
	vec < int > left;
	vec < int > right;
	for(int  i : tb){
		if(i != A && i != B){
			if(Query(A,B,i) == A){
				left.pb(i);
			}else{
				right.pb(i);
			}
		}
	}
	left.pb(A);
	sort(all(left));	
	solves(left);
	left.clear();
	right.pb(B);
	sort(all(right));
	solves(right);
	right.clear();
}
 
 
void Solve(int n){
	vec < int > asd;
	for(int i= 0; i <n ; i++)asd.pb(i);
	solves(asd);
	for(pii ed : eds){
		Bridge(min(ed.fr,ed.sc),max(ed.fr,ed.sc));
	}
	asd.clear();
}

Compilation message (stderr)

meetings.cpp: In function 'int find_center(std::vector<int>&)':
meetings.cpp:47:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < cnt.size() ; i++){
                 ~~^~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 12 / 12
• Subtask 4: 71 / 71