#include <bits/stdc++.h>
using namespace std;
// #define int long long
// #define f first
// #define s second
mt19937 gnd(time(NULL));
const int N = 1e4+5;
vector<int> adj[N];
int v[N], r[N], w[N];
vector<pair<long long int, int>> dis(N, {1e18+7, 0});
int pos = 0;
// long long int get_distance(int a, int b);
int get_distance(int a, int b){
cout << "? " << a << " " << b << endl;
int d;
cin >> d;
return d;
}
void un(int a, int b, int dis){
adj[a].push_back(b);
// adj[b].push_back(a);
v[pos]=a;
r[pos]=b;
w[pos]=dis;
pos++;
}
void dfs(int u, int p, int pos, int pd){
int st = dis[pos].second, dd = dis[pos].first;
if(adj[u].size() == 0){
un(u, st, pd);
return;
}
if(adj[u].size() == 1){
int x = adj[u][0];
int d = get_distance(x, st);
if(d < pd) dfs(x, u, pos, d);
else{
un(u, st, pd);
return;
}
}
if(adj[u].size() == 2){
int x = adj[u][0];
int d = get_distance(x, st);
if(d < pd) dfs(x, u, pos, d);
else{
int r = get_distance(adj[u][1], st);
dfs(adj[u][1], u, pos, r);
}
}
}
void find_roads(int n, int q, int A[], int B[], int W[]){
for(int i = n-1; i < N; i++) dis[i].first = 1e18+7;
// vector<pair<long long int, int>> dis (n-1);
for(int i = 0; i < n-1; i++){
long long int d = get_distance(1, i+2);
dis[i]={d, i+2};
}
sort(dis.begin(), dis.end());
un(1, dis[0].second, dis[0].first);
for(int i = 1; i < n-1; i++){
dfs(1, -1, i, dis[i].first);
}
// for(int i = 0; i < n-1; i++){
// cout << v[i] << " " << r[i] << " " << w[i] << endl;
// }
int aa[n-1], bb[n-1], cc[n-1];
for(int i = 0; i < n-1; i++){
aa[i] = v[i];
bb[i] = r[i];
cc[i] = w[i];
// cout << v[i] << " " << r[i] << " " << w[i] << endl;
}
A = aa;
B = bb;
W = cc;
return;
}
// void fr(int n, int q){
// int a[n], b[n], w[n];
// find_roads(n, q, a, b, w);
// // cout << "s" << endl;
// }
// signed main(){
// // ios::sync_with_stdio(0);
// // cin.tie(0);
// // cout.tie(0);
// int t = 1;
// // cin >> t;
// while(t--){
// int n, q;
// cin >> n >> q;
// fr(n, q);
// }
// }
Compilation message
citymapping.cpp: In function 'void dfs(int, int, int, int)':
citymapping.cpp:38:31: warning: unused variable 'dd' [-Wunused-variable]
38 | int st = dis[pos].second, dd = dis[pos].first;
| ^~
/usr/bin/ld: /tmp/ccfBWs9G.o: in function `get_distance(int, int)':
grader.cpp:(.text+0x470): multiple definition of `get_distance(int, int)'; /tmp/ccXrXGGF.o:citymapping.cpp:(.text+0x5a0): first defined here
collect2: error: ld returned 1 exit status
