#include <iostream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <numeric>
#include <cstring>
#include <string>
#include <cmath>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include "citymapping.h"
using namespace std;
#define ll long long
#define ull unsigned long long
#define f first
#define s second
#define PF push_front
#define PB push_back
#define MP make_pair
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define max(a, b) ((a > b)? a : b)
#define min(a, b) ((a < b)? a : b)
#define max3(a, b, c) max(max(a, b), c)
#define min3(a, b, c) min(min(a, b), c)
const int N = 1e3 + 5;
const int M = 1e9 + 7;
const int inf = 0x3f3f3f3f;
const ll int INF = 1e18;
vector<vector<pair<int, int>>> adj(1005, vector<pair<int, int>>());
vector<int> sz(1005);
vector<bool> block(1005, false);
void get_sz(int cur){
sz[cur] = 1;
for(auto [child, _] : adj[cur]){
if(block[child]) continue;
get_sz(child);
sz[cur] += sz[child];
}
}
void find_roads(int n, int q, int a[], int b[], int w[]){
vector<pair<ll, int>> dis;
vector<ll> dis_to(n+1);
for(int i = 2; i <= n; i++){
ll temp = get_distance(1, i);
dis.PB(MP(temp, i));
dis_to[i] = temp;
}
sort(all(dis));
adj[1].PB(MP(dis[0].s, dis[0].f));
for(int i = 1; i < n-1; i++){
for(int j = 1; j <= n; j++) block[j] = false;
int root = 1;
int cur = dis[i].s;
while(true){
for(int j = 1; j <= n; j++) sz[j] = 0;
get_sz(root);
if(sz[root] == 1) break;
int mid = root;
for(int j = 1; j <= n; j++) if(sz[j] > 0){
int dif = abs(sz[j] - (sz[root]/2));
if(dif < abs(sz[mid] - (sz[root]/2))){
mid = j;
}
}
ll dist = get_distance(cur, mid);
if(dis_to[mid] + dist == dis_to[cur]){
// Correct subtree
root = mid;
}else {
// Prune subtree
block[mid] = true;
}
}
adj[root].PB(MP(cur, dis_to[cur] - dis_to[root]));
}
int cnt = 0;
for(int i = 1; i <= n; i++){
for(auto [child, weight] : adj[i]){
a[cnt] = i;
b[cnt] = child;
w[cnt] = weight;
cnt++;
}
}
}
