Submission #788084

#	Time	Username	Problem	Language	Result	Execution time	Memory
788084		GusterGoose27	Towns (IOI15_towns)	C++17	35 / 100	16 ms	352 KiB

towns

#include "towns.h"

#include <bits/stdc++.h>

using namespace std;

const int MAXN = 120;
const int inf = 1e9;
int dist[MAXN][2];

int _abs(int a) {
	return a < 0 ? -a : a;
}

int hubDistance(int n, int sub) {
	int l = 0;
	int d = 0;
	for (int i = 1; i < n; i++) {
		int cur = getDistance(0, i);
		if (cur > d) {
			l = i;
			d = cur;
		}
	}
	assert(getDistance(0, l) == d);
	dist[l][0] = 0;
	dist[0][0] = d;
	int r = 0;
	for (int i = 1; i < n; i++) {
		if (i == l) continue;
		dist[i][0] = getDistance(i, l);
		if (dist[i][0] > dist[r][0]) r = i;
	}
	dist[r][1] = 0;
	for (int i = 0; i < n; i++) {
		if (i == r) continue;
		if (i == l) {
			dist[i][1] = dist[r][0];
			continue;
		}
		dist[i][1] = getDistance(i, r);
	}
	int mn = inf;
	for (int i = 0; i < n; i++) {
		mn = min(mn, _abs(dist[i][0]-dist[i][1]));
	}
	// return (mn+dist[r][0])/2;
	int sz[4]; fill(sz, sz+4, 0);
	for (int i = 0; i < n; i++) {
		int diff = dist[i][1]-dist[i][0];
		if (diff > mn) sz[0]++;
		else if (diff == mn) sz[1]++;
		else if (diff == -mn) sz[2]++;
		else sz[3]++;
	}
	// assert(dist[l][1] == dist[r][0]);
	// assert(l != r && l != 0);
	assert((mn+dist[r][0])%2 == 0);
	int R = (dist[r][0]+mn)/2;
	if (sz[1] && (sz[0] <= n/2 && sz[1] <= n/2 && sz[2]+sz[3] <= n/2)) return R;
	if (sz[2] && (sz[0]+sz[1] <= n/2 && sz[2] <= n/2 && sz[3] <= n/2)) return R;
	return -R;
}

Compilation message (stderr)

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:15:28: warning: unused parameter 'sub' [-Wunused-parameter]
   15 | int hubDistance(int n, int sub) {
      |                        ~~~~^~~

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