Submission #288510

#	Time	Username	Problem	Language	Result	Execution time	Memory
288510		Saboon	Towns (IOI15_towns)	C++17	25 / 100	20 ms	512 KiB

towns

#include "towns.h"
#include<bits/stdc++.h>
using namespace std;
const int inf = 2e8 + 10;
int n, d[110][110];

int Dis(int v, int u){
	if (v == u or d[v][u] > 0)
		return d[v][u];
	return d[v][u] = d[u][v] = getDistance(v,u);
}

int getDis(int v, int u, int w){
	return (Dis(v,u)+Dis(v,w)-Dis(u,w))/2;
}

int hubDistance(int N, int sub){
	memset(d, 0, sizeof d);
	n = N;
	int Q1 = 0, Q2 = 0;
	for (int i = 1; i < n; i++)
		if (Dis(0,i) > Dis(0,Q1))
			Q1 = i;
	for (int i = 1; i < n; i++)
		if (Dis(Q1,i) > Dis(Q1,Q2))
			Q2 = i;
	int R = inf;
	vector<int> a;
	for (int v = 0; v < n; v++){
		if (v == Q1 or v == Q2)
			continue;
		int A = getDis(Q1, Q2, v), B = getDis(Q2, Q1, v);
		a.push_back(A);
		R = min(R,max(A,B));
	}
	if (sub <= 2)
		return R;
	sort(a.begin(), a.end());
	a.resize(unique(a.begin(),a.end())-a.begin());
	int m = 1;
	for (auto it : a){
		int now = 0;
		for (int v = 0; v < n; v++){
			if (v == Q1 or v == Q2)
				continue;
			if (getDis(Q1, Q2, v) == it)
				now ++;
		}
		int t = min(it,Dis(Q1,Q2)-it);
		if (t == R and now <= n/2 and m <= n/2 and (n-now-m) <= n/2)
			return R;
		m += now;
	}
	return -R;
}

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