# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
615629 | Apiram | Towns (IOI15_towns) | C++14 | 0 ms | 0 KiB |
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 <bits/stdc++.h>
using namespace std;
int hubDistance(int N, int sub) {
int root = 0;
vector<int>dist(N);
for (int i = 0;i<N;++i){
if (i == root)dist[i] = 0;
else dist[i] = getDistance(i,root);
}
for (int i = 0;i<N;++i){
if (dist[i] > dist[root]){
root = i;
}
}
for (int i = 0;i<N;++i){
if (i == root)dist[i] = 0;
else dist[i] = getDistance(i,root);
}
int root2 = root;
for (int i = 0;i<N;++i){
if (dist[i] > dist[root2])root2 = i;
}
int answer = dist[root2];
vector<int>dist2(N);
for (int i = 0;i<N;++i){
if (i == root2){
dist2[i] = 0;
}
else{
dist2[i] = getDistance(root2,i);
}
}
for (int i = 0;i<N;++i){
int x = (dist[i] + dist2[i] - dist[root2])/2;
answer = min(answer,max(dist[i] - x,dist2[i] - x));
}
for (int i = 0;i<N;++i){
int x = (dist[i] + dist2[i] - dist[root2])/2;
if (answer == max(dist[i] - x,dist2[i] - x)){
int sub1 = 0,sub2 = 0,sub3 = 0,sub4 = 0;
for (int j = 0;j<N;++j){
if (dist[j] <= dist[i] - x && dist2[j] > dist2[i] - x ){
sub1++;
}
else if (dist2[j]<=dist2[i] - x && dist[j] > dist[i] - x){
sub2++;
}
else if (sub3 < sub4)sub3++;
else sub4++;
}
if (max({sub3,sub1,sub2,sub4}) <=N/2){
return answer;
}
}
}
return -answer;