This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include "towns.h"
#include <vector>
#include <iostream>
using namespace std;
const int MAX_DIST = 1e6+5;
vector< vector<int> > mat;
int get_dist(int a, int b) {
	if (mat[a][b] == -1)
		return mat[a][b] = mat[b][a] = getDistance(a, b);
	else
		return mat[a][b];
}
int hubDistance(int N, int sub) {
	mat.assign(N, vector<int>(N, -1));
	int u = -1;
	int mx = -1;
	for (int i = 0; i < N; ++i) {
		if (get_dist(0, i) > mx) {
			u = i;
			mx = get_dist(0, i);
		}
	}
	int v = -1;
	mx = -1;
	for (int i = 0; i < N; ++i) {
		if (get_dist(u, i) > mx) {
			v = i;
			mx = get_dist(u, v);
		}
	}
	vector<int> freq(mx+1, 0);
	for (int i = 0; i < N; ++i) {
		int k = get_dist(i, u);
		int l = get_dist(i, v);
		++freq[mx-(l-(k+l-mx)/2)];
	}
	int ans = 0;
	for (int i = 0; i < mx; ++i) {
		ans = max(ans, max(i, mx-i));
	}
	return ans;
}
Compilation message (stderr)
towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:18:28: warning: unused parameter 'sub' [-Wunused-parameter]
 int hubDistance(int N, int sub) {
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