| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 743386 | tolbi | Fun Tour (APIO20_fun) | C++17 | 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.
#pragma optimize("Bismillahirrahmanirrahim")
//█▀█─█──█──█▀█─█─█
//█▄█─█──█──█▄█─█■█
//█─█─█▄─█▄─█─█─█─█
//Allahuekber
//ahmet23 orz...
//Sani buyuk Osman Pasa Plevneden cikmam diyor.
//FatihSultanMehmedHan
//YavuzSultanSelimHan
//AbdulhamidHan
#define author tolbi
#include <bits/stdc++.h>
using namespace std;
template<typename X, typename Y> istream& operator>>(istream& in, pair<X,Y> &pr) {return in>>pr.first>>pr.second;}
template<typename X, typename Y> ostream& operator<<(ostream& os, pair<X,Y> pr) {return os<<pr.first<<" "<<pr.second;}
template<typename X, typename Y> pair<X,Y> operator+(pair<X,Y> a, pair<X,Y> b) {pair<X,Y> c; c.first=a.first+b.first,c.second=a.second+b.second;return c;}
template<typename X, typename Y> pair<X,Y> operator-(pair<X,Y> a, pair<X,Y> b) {pair<X,Y> c; c.first=a.first-b.first,c.second=a.second-b.second;return c;}
template<typename X, typename Y> void operator+=(pair<X,Y> &a, pair<X,Y> b){a.first+=b.first,a.second+=b.second;}
template<typename X, typename Y> void operator-=(pair<X,Y> &a, pair<X,Y> b){a.first-=b.first,a.second-=b.second;}
template<typename X> istream& operator>>(istream& in, vector<X> &arr) {for(auto &it : arr) in>>it; return in;}
template<typename X> ostream& operator<<(ostream& os, vector<X> arr) {for(auto &it : arr) os<<it<<" "; return os;}
template<typename X, size_t Y> istream& operator>>(istream& in, array<X,Y> &arr) {for(auto &it : arr) in>>it; return in;}
template<typename X, size_t Y> ostream& operator<<(ostream& os, array<X,Y> arr) {for(auto &it : arr) os<<it<<" "; return os;}
#define int long long
#define endl '\n'
#define vint(x) vector<int> x
#define deci(x) int x;cin>>x;
#define decstr(x) string x;cin>>x;
#define cinarr(x) for (auto &it : x) cin>>it;
#define coutarr(x) for (auto &it : x) cout<<it<<" ";cout<<endl;
#define sortarr(x) sort(x.begin(),x.end())
#define sortrarr(x) sort(x.rbegin(),x.rend())
#define det(x) cout<<"NO\0YES"+x*3<<endl;
#define INF LONG_LONG_MAX
#define rev(x) reverse(x.begin(),x.end());
#define ios ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define tol(bi) (1LL<<((int)(bi)))
const int MOD = 1e9+7;
mt19937 ayahya(chrono::high_resolution_clock().now().time_since_epoch().count());
#include "swap.h"
vector<int> par;
vector<int> dep;
vector<vector<pair<int,int>>> st;
int LOG;
int find(int node){
if (par[node]==node) return node;
return par[node]=find(par[node]);
}
vector<int> val;
void init(int32_t N, int32_t M, vector<int32_t> U, vector<int32_t> V, vector<int32_t> W) {
vector<pair<int,pair<int,int>>> edges(M);
LOG=log2(N)+3;
par.resize(N);
dep.resize(N);
iota(par.begin(), par.end(), 0);
vector<vector<pair<int,int>>> arr(N);
val.resize(N,INF);
for (int i = 0; i < M; i++){
edges[i]={W[i],{U[i],V[i]}};
}
sortarr(edges);
for (int i = 0; i < M; i++){
auto [u,v] = edges[i].second;
int w = edges[i].first;
if (find(u)==find(v)){
if (val[u]==INF) val[u]=w;
if (val[v]==INF) val[v]=w;
continue;
}
arr[u].push_back({v,w});
arr[v].push_back({u,w});
u=find(u);
v=find(v);
if (ayahya()%2) swap(u,v);
par[u]=v;
}
st.resize(N,vector<pair<int,int>>(LOG,{-1,-1}));
auto dfs = [&](int node, int lnode, auto dfs)->void{
if (lnode==-1) dep[node]=0;
else dep[node]=dep[lnode]+1;
for (int i = 0; i < arr[node].size(); i++){
if (arr[node][i].first==lnode) continue;
dfs(arr[node][i].first,node,dfs);
st[arr[node][i].first][0]={node,arr[node][i].second};
val[node]=min(val[node],max(val[arr[node][i].first],arr[node][i].second));
}
};
auto dfs2 = [&](int node, int lnode, auto dfs2)->void{
if (node){
val[node]=min(val[node],max(val[lnode],st[node][0].second));
}
for (int i = 0; i < arr[node].size(); i++){
if (arr[node][i].first==lnode) continue;
dfs2(arr[node][i].first,node,dfs2);
}
};
dfs(0,-1,dfs);
dfs2(0,-1,dfs2);
for (int bit = 1; bit < LOG; bit++){
for (int i = 0; i < N; i++){
if (st[i][bit-1].first==-1) continue;
st[i][bit].first=st[st[i][bit-1].first][bit-1].first;
st[i][bit].second=max(st[i][bit-1].second,st[st[i][bit-1].first][bit-1].second);
}
}
}
pair<int,int> kthpar(int node, int k){
int rval = 0ll;
for (int bit = LOG-1; bit >= 0; bit--){
if (tol(bit)&k){
rval=max(rval,st[node][bit].second);
node=st[node][bit].first;
}
}
return {node,rval};
}
pair<int,int> lca(int a, int b){
if (dep[a]<dep[b]) swap(a,b);
pair<int,int> pr = kthpar(a,dep[a]-dep[b]);
a=pr.first;
int ans = pr.second;
if (a==b) return {a,ans};
for (int bit = LOG-1; bit >= 0; bit--){
if (st[a][bit].first==st[b][bit].first) continue;
ans=max(ans,st[a][bit].second);
ans=max(ans,st[b][bit].second);
a=st[a][bit].first;
b=st[b][bit].first;
}
ans=max(ans,st[a][0].second);
ans=max(ans,st[b][0].second);
return {st[a][0].first,ans};
}
int32_t getMinimumFuelCapacity(int32_t X, int32_t Y){
pair<int,int> ans = lca(X,Y);
if (max(ans.second,val[ans.first])==INF) return -1;
return max(ans.second,val[ans.first]);
}
#ifdef tolbi
int32_t main() {
int32_t N, M;
assert(2 == scanf("%d %d", &N, &M));
vector<int32_t> U(M), V(M), W(M);
for (int32_t i = 0; i < M; ++i) {
assert(3 == scanf("%d %d %d", &U[i], &V[i], &W[i]));
}
int32_t Q;
assert(1 == scanf("%d", &Q));
vector<int32_t> X(Q), Y(Q);
for (int32_t i = 0; i < Q; ++i) {
assert(2 == scanf("%d %d", &X[i], &Y[i]));
}
init(N, M, U, V, W);
vector<int32_t> minimum_fuel_capacities(Q);
for (int32_t i = 0; i < Q; ++i) {
minimum_fuel_capacities[i] = getMinimumFuelCapacity(X[i], Y[i]);
}
for (int32_t i = 0; i < Q; ++i) {
printf("%d\n", minimum_fuel_capacities[i]);
}
return 0;
}
#endif