#include "factories.h"
#include <bits/stdc++.h>
using namespace std;
using ll=long long;
#define vec vector
#define pb push_back
#define rng(i,a,b) for(int i=(a);i<(b);i++)
#define rep(i,n) rng(i,0,n)
#define siz(a) a.size()
template<typename T>
void chmin(T& a,T b){a=min(a,b);}
template<typename T>
void chmax(T& a,T b){a=max(a,b);}
int n;
vec<int>e[600000];
ll dpt[600000];
vec<int>eul;
vec<ll>dpto;
int out[600000];
int spt[1100000][20];
int lgt[1100000];
int lca(int a,int b){
int x=out[a],y=out[b];
if(x>y) swap(x,y);
int k=lgt[(y-x+1)];
int s=spt[x][k],t=spt[y-(1<<k)+1][k];
if(dpto[s]<dpto[t]) return eul[s];
else return eul[t];
}
ll dist(int a,int b){
return dpt[a]+dpt[b]-2*dpt[lca(a,b)];
}
void Init(int N, int A[], int B[], int D[]) {
n=N;
map<pair<int, int>, ll>mp;
rep(i,n-1){
e[A[i]].pb(B[i]);
e[B[i]].pb(A[i]);
mp[make_pair(min(A[i],B[i]),max(A[i],B[i]))]=D[i];
}
auto dfs=[&](int x,int p,ll d,auto& dfs)->void{
dpt[x]=d;
out[x]=siz(eul);
eul.pb(x);dpto.pb(d);
for(auto g:e[x]){
if(g==p) continue;
ll k=mp[make_pair(min(x,g),max(x,g))];
dfs(g,x,d+k,dfs);
eul.pb(x);dpto.pb(d);
}
};
dfs(0,-1,0,dfs);
rep(i,siz(eul)) spt[i][0]=i;
rng(i,2,siz(eul)+1) lgt[i]=lgt[i>>1]+1;
rep(j,19) for(int i=0;i+(1<<(j+1))<=siz(eul);i++){
int a=spt[i][j],b=spt[i+(1<<j)][j];
if(dpto[a]<dpto[b]) spt[i][j+1]=a;
else spt[i][j+1]=b;
}
}
long long Query(int S, int X[], int T, int Y[]) {
constexpr ll inf=1e17;
ll ans=inf;
rep(i,S)rep(j,T){
chmin(ans,dist(X[i],Y[j]));
}
return ans;
}
int A[200000],B[200000],D[200000];
signed main(){
cin>>n;
rep(i,n-1){
cin>>A[i]>>B[i];D[i]=1;
A[i]--;B[i]--;
}
Init(n,A,B,D);
int q;cin>>q;
int X[1],Y[1];
rep(i,q){
cin>>X[0]>>Y[0];
X[0]--;Y[0]--;
cout<<Query(1,X,1,Y)+1<<endl;
}
}
Compilation message
factories.cpp: In function 'void Init(int, int*, int*, int*)':
factories.cpp:7:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
7 | #define rng(i,a,b) for(int i=(a);i<(b);i++)
| ^
factories.cpp:8:18: note: in expansion of macro 'rng'
8 | #define rep(i,n) rng(i,0,n)
| ^~~
factories.cpp:58:3: note: in expansion of macro 'rep'
58 | rep(i,siz(eul)) spt[i][0]=i;
| ^~~
factories.cpp:7:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
7 | #define rng(i,a,b) for(int i=(a);i<(b);i++)
| ^
factories.cpp:59:3: note: in expansion of macro 'rng'
59 | rng(i,2,siz(eul)+1) lgt[i]=lgt[i>>1]+1;
| ^~~
factories.cpp:61:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
61 | rep(j,19) for(int i=0;i+(1<<(j+1))<=siz(eul);i++){
| ^
/tmp/ccnqLHUp.o: In function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/ccAaXqLF.o:factories.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
