| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1269932 | sasde | Swapping Cities (APIO20_swap) | C++20 | 0 ms | 0 KiB |
#include<bits/stdc++.h>
#include "swap.h"
using namespace std;
bool M1;
#define PI 3.14159265358979323846
#define sz(a) (int)a.size()
#define all(x) x.begin(),x.end()
#define ii pair<int,int>
#define iii pair<int,ii>
#define iv pair<ii,ii>
#define se second
#define fi first
#define ffi fi.fi
#define sfi se.fi
#define sse se.se
#define fse fi.se
#define lt(i, c, d) for(int i = c; i <= d; ++i)
#define fl(i, c, d) for(int i = d; i >= c; --i)
#define pb push_back
#define emb emplace_back
#define emf emplace_front
#define em emplace
#define look_memory cerr<<abs(&M2-&M1)/1024.0/1024<<'\n'
#define look_time cerr << "TIME : " << clock() * 0.001 << "s" <<'\n'
const int N=3e5+5,lg=18,mod=1e9+7;
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int u,int v){
return u+rd()%(v-u+1);
}
int dx[]={1,0,-1,0,1,1,-1,-1};
int dy[]={0,-1,0,1,1,-1,1,-1};
bool M2;
struct pt
{
int u,v,w;
};
vector<int>ver[N];
int r[N],n,st[N],ed[N],a[N],root[N];
bool check[N],ok[N];
int acs(int u){
return r[u]==u?u:r[u]=acs(r[u]);
}
bool join(int u,int v,int pos){
int pu=acs(u);
int pv=acs(v);
if(pu==pv){
root[pu]=pos;
ok[pu]=true;
return true;
}
ok[pu]|=ok[pv];
if(!ok[pu]){
if(st[pu]==u&&(st[pv]==v||ed[pv]==v)){
st[pu]=st[pv]==v?st[pv]:ed[pv];
}
else{
if(ed[pu]==u&&(st[pv]==v||ed[pv]==v)){
ed[pu]=st[pv]==v?st[pv]:ed[pv];
}
else {
ok[u]=true;
}
}
}
root[u]=pos;
r[v]=u;
return ok[u];
}
int up[N][lg+5],h[N];
void dfs(int u,int cha)
{
// cout <<u<<'\n';
for(auto v:ver[u])
{
if(v==cha)continue;
up[v][0]=u;
h[v]=h[u]+1;
dfs(v,u);
}
}
int lca(int u,int v)
{
if(h[u]<h[v])swap(u,v);
for(int j=lg;j>=0;--j)
{
if(h[u]-h[v]>=(1<<j))
u=up[u][j];
}
if(u==v)return u;
for(int j=lg;j>=0;--j)
{
if(up[u][j]!=up[v][j])
{
u=up[u][j];
v=up[v][j];
}
}
return up[u][0];
}
void build(int val){
dfs(val,-1);
for(int j=1;j<=lg;++j)
for(int i=1;i<=val;++i)up[i][j]=up[up[i][j-1]][j-1];
}
vector<pt>b;
int nod;
void init(int &node,int &edge,vector<int>&u,vector<int>&v,vector<int>&w){
nod=node;
for(int i=0;i<edge;++i){
++u[i];
++v[i];
b.pb({u[i],v[i],w[i]});
}
sort(all(b),[&](const pt &x,const pt &y){
return x.w<y.w;
});
for(int i=1;i<=node;++i){
r[i]=i;
st[i]=ed[i]=i;
root[i]=i;
}
for(int i=0;i<edge;++i){
int u=acs(b[i].u);
int v=acs(b[i].v);
// cout <<i+1+node<<" "<<root[u]<<" "<<root[v]<<'\n';
if(u==v){
ver[i+1+node].emb(root[u]);
check[i+1+node]=join(b[i].u,b[i].v,i+1+node);
}
else{
ver[i+1+node].emb(root[u]);
ver[i+1+node].emb(root[v]);
check[i+1+node]=join(b[i].u,b[i].v,i+1+node);
}
// cout <<i+1+edge<<'\n';
}
build(node+edge);
check[0]=true;
}
int getMinimumFuelCapacity(int x,int y){
++x;
++y;
int l=lca(x,y);
// cout <<x<<" "<<y<<" "<<l<<'\n';
if(check[l]){
return b[l-nod-1].w;
}
for(int j=lg;j>=0;--j){
int x=up[l][j];
if(check[x])continue;
l=x;
}
l=up[l][0];
if(l==0)return -1;
return b[l-nod-1].w;
}
// main()
// {
// srand(time(0));
// ios_base::sync_with_stdio(false);
// cin.tie(NULL);
// cout.tie(NULL);
// #define task "aws"
// if(fopen(task".inp","r")){
// freopen(task".inp","r",stdin);
// freopen(task".out","w",stdout);
// }
// int node,edge,query;
// cin >> node >> edge;
// vector<int>a,b,c;
// for(int i=1;i<=edge;++i){
// int u,v,w;
// cin >> u >> v >> w;
// a.emb(u);
// b.emb(v);
// c.emb(w);
// }
// init(node,edge,a,b,c);
// cin >> query;
// // cout <<query<<'\n';
// while(query--){
// int u,v;
// cin >> u >> v;
// cout<<getMinimumFuelCapacity(u,v);cout<<'\n';
// }
// int t=1;
// // cin >> t;
// look_memory;
// look_time;
// }