3.6 KB | 3682 chars
#include <bits/stdc++.h>
#define for1(s,n) for(int i = s; i < n; i++)
#define for1j(s,n) for(int j = s; j < n; j++)
#define foreach(k) for(auto i : k)
#define foreachj(k) for(auto j : k)
#define pb(a) push_back(a)
#define sz(a) a.size()
#define MX 110000
#define INF (ll)1e18
#define MX_LOG_K 24
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef vector <int> iv1;
typedef vector <vector<int>> iv2;
typedef vector <ll> llv1;
typedef unsigned int uint;
typedef vector <ull> ullv1;
typedef vector <vector <ull>> ullv2;
ll N,M;
ll parent[MX_LOG_K+2][MX];
ll minWeight[MX_LOG_K+2][MX];
ll maxWeight[MX_LOG_K+2][MX];
ll depth[MX];
ll dis[MX];
vector<vector<pair<ll, ll>>> edge;
ll root = 1ll;
void setParent(ll here, ll p, ll weight) {
depth[here] = depth[p] + 1;
dis[here] = weight;
foreach(edge[here]) {
if(i.first == p) continue;
setParent(i.first, here, weight + i.second);
minWeight[0][i.first] = min(minWeight[0][i.first], i.second);
maxWeight[0][i.first] = max(maxWeight[0][i.first], i.second);
parent[0][i.first] = here;
}
}
ll getLCA(ll x, ll y) {
if(depth[x] > depth[y]) swap(x, y);
for(int i = MX_LOG_K; i>=0; i--) {
if(depth[y] - depth[x] >= (1ll << i)) {
y = parent[i][y];
}
}
if(x == y) return x;
for(int i= MX_LOG_K; i>=0; i--) {
if(parent[i][x] != parent[i][y]) {
x = parent[i][x];
y = parent[i][y];
}
}
return parent[0][x];
}
ll getMinWeightToLCA(ll x, ll y) {
ll ret = INF;
if(depth[x] > depth[y]) swap(x, y);
for(int i = MX_LOG_K; i>=0; i--) {
if(depth[y] - depth[x] >= (1ll << i)) {
ret = min(ret, minWeight[i][y]);
y = parent[i][y];
}
}
if(x == y) return ret;
for(int i = MX_LOG_K; i>=0; i--) {
if(parent[i][x] != parent[i][y]) {
ret = min(ret, min(minWeight[i][x],minWeight[i][y]));
x = parent[i][x];
y = parent[i][y];
}
}
ret = min(ret, min(minWeight[0][x], minWeight[0][y]));
return ret;
}
ll getMaxWeightToLCA(ll x, ll y) {
ll ret = -INF;
if(depth[x] > depth[y]) swap(x, y);
for(int i = MX_LOG_K; i>=0; i--) {
if(depth[y] - depth[x] >= (1ll << i)) {
ret = max(ret, maxWeight[i][y]);
y = parent[i][y];
}
}
if(x == y) return ret;
for(int i = MX_LOG_K; i>=0; i--) {
if(parent[i][x] != parent[i][y]) {
ret = max(ret, max(maxWeight[i][x],maxWeight[i][y]));
x = parent[i][x];
y = parent[i][y];
}
}
ret = max(ret, max(maxWeight[0][x], maxWeight[0][y]));
return ret;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> N;
edge.resize(N+1);
for1(0, N - 1) {
ll a, b, c;
cin >> a >> b >> c;
edge[a].push_back({b, c});
edge[b].push_back({a, c});
}
for1(0, MX_LOG_K+1) {
for1j(0,N+1) {
minWeight[i][j] = INF;
maxWeight[i][j] = -INF;
}
}
setParent(root, 0, 0);
for(int k = 1; k < MX_LOG_K; k++) {
for(int i = 1; i <= N; i++) {
parent[k][i] = parent[k-1][parent[k-1][i]];
minWeight[k][i] = min(minWeight[k][i], min(minWeight[k-1][i], minWeight[k-1][parent[k-1][i]]));
maxWeight[k][i] = max(maxWeight[k][i], max(maxWeight[k-1][i], maxWeight[k-1][parent[k-1][i]]));
}
}
cin >> M;
while(M--) {
ll a, b;
cin >> a >> b;
cout << getMinWeightToLCA(a, b) << " " << getMaxWeightToLCA(a,b) << "\n";
}
}