Submission #1018732

#	Time	Username	Problem	Language	Result	Execution time	Memory
1018732		parsadox2	Towns (IOI15_towns)	C++17	13 / 100	10 ms	1116 KiB

towns

#include "towns.h"
#include <bits/stdc++.h>

#define F first
#define S second

using namespace std;

const int N = 1e2 + 20;
int n , dis[N][N] , r[N] , L[N] , R[N] , cnt[N];

bool Solve(int D)
{
	int lef = 0 , rig = 0 , mid = 0;
	for(int x = 0 ; x < n ; x++)
		cnt[x] = 0;
	vector <int> vec;
	for(int x = 0 ; x < n ; x++)
	{
		if(L[x] < D)
			lef++;
		else if(L[x] > D)
			rig++;
		else
		{
			bool flg = false;
			for(auto u : vec)
			{
				dis[u][x] = dis[x][u] = getDistance(u , x);
				if(dis[u][x] != r[u] + r[x])
				{
					flg = true;
					cnt[u]++;
					break;
				}
			}
			if(!flg)
			{
				vec.push_back(x);
				cnt[x] = 1;
			}
		}
	}
	for(int i = 0 ; i < n ; i++)
		mid = max(mid , cnt[i]);
	return (lef <= n / 2 && rig <= n/2 && mid <= n / 2);
}

int hubDistance(int nn , int sub) {
	n = nn;
	pair <int , int> D = make_pair(0 , 1);
	for(int i = 1 ; i < n ; i++)
	{
		dis[0][i] = dis[i][0] = getDistance(0 , i);
		if(dis[0][i] > dis[D.F][D.S])
			D = make_pair(0 , i);
	}
	for(int i = 0 ; i < n ; i++)  if(i != D.S)
	{
		dis[i][D.S] = dis[D.S][i] = getDistance(i , D.S);
		if(dis[i][D.S] > dis[D.F][D.S])
			D = make_pair(i , D.S);
	}
	int ans = dis[D.F][D.S];
	for(int x = 0 ; x < n ; x++)
	{
		dis[x][D.F] = dis[D.F][x] = getDistance(x , D.F);
		r[x] = (dis[x][D.F] + dis[x][D.S] - dis[D.F][D.S]) / 2;
		L[x] = dis[x][D.F] - r[x];
		R[x] = dis[x][D.S] - r[x];
		//cout << x << " : " << L[x] << " " << R[x] << endl;
		ans = min(ans , max(L[x] , R[x]));
	}
	ans = -ans;
	set <int> st;
	for(int x = 0 ; x < n ; x++)  if(L[x] == abs(ans) || R[x] == abs(ans))
	{
		if(st.find(L[x]) != st.end())
			continue;
		st.insert(L[x]);
		if(Solve(L[x]))
		{
			break;
			ans = abs(ans);
		}
	}
	return ans;
}

Compilation message (stderr)

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:49:30: warning: unused parameter 'sub' [-Wunused-parameter]
   49 | int hubDistance(int nn , int sub) {
      |                          ~~~~^~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 39