Submission #966646

#	Time	Username	Problem	Language	Result	Execution time	Memory
966646		penguin133	Swapping Cities (APIO20_swap)	C++17	6 / 100	230 ms	41840 KiB

swap

#include <bits/stdc++.h>
using namespace std;
//#include "swap.h"
//#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
 
vector <int> waiting[200005];
int par[200005], val[200005], deg[200005], good[200005], up[20][200005], dep[200005];
int cnt = 1;
pi adj[200005];
int getr(int x){return par[x] == x ? x : par[x] = getr(par[x]);}
void merge(int a, int b, int c){
	//cout << a << ' ' << b << ' ' << c << '\n';
	a = getr(a); b = getr(b);
	if(a == b)return;
	par[a] = par[b] = up[0][a] = up[0][b] = cnt;
	if((int)waiting[a].size() < (int)waiting[b].size())swap(a, b);
	swap(waiting[cnt], waiting[a]);
	for(auto j : waiting[b])waiting[cnt].push_back(j);
	val[cnt] = c;
	adj[cnt] = {a, b};
	cnt++;
}
 
int par2[200005];
int g2(int x){return par2[x] == x ? x : par2[x] = g2(par2[x]);}
void m2(int a, int b){par2[g2(b)] = g2(a);}
 
void dfs(int x, int d){
	//cout << x << '\n';
	dep[x] = d;
	if(!adj[x].fi)return;
	dfs(adj[x].fi, d + 1);
	dfs(adj[x].se, d + 1);
}
 
int lca(int u, int v){
	if(dep[u] > dep[v])swap(u, v);
	int df = dep[v] -dep[u];
	for(int i = 0; i < 19; i++)if(df >> i & 1)v = up[i][v];
	if(u ==v )return u;
	for(int i = 19; i >=0 ; i--)if(up[i][u] != up[i][v])u = up[i][u], v = up[i][v];
	return up[0][u];
}
 
void init(int N, int M,
          std::vector<int> U, std::vector<int> V, std::vector<int> W) {
	vector <pii> bb;
	cnt = N;
	for(int i = 0; i < 2 * N; i++)par[i] = par2[i] = i;
	for(int i = 0; i < M; i++)bb.push_back({W[i], {U[i], V[i]}});
	sort(bb.begin(), bb.end());
	for(auto i : bb){
		int a = i.se.fi, b = i.se.se, w = i.fi;
		if(g2(a) == g2(b)){
			good[getr(a)] = 1;
			good[getr(b)] = 1;
			queue <int> q;
			q.push(getr(a));
			q.push(getr(b));
			merge(a, b, w);
			while(!q.empty()){
				int x = q.front(); q.pop();
				//if(good[x])continue;
				//good[x] = 1;
				for(auto j : waiting[x]){
					if(!good[j]){
						good[j] = 1;
						merge(x, j, w);
						q.push(j);
					}
				}
				waiting[x].clear();
			}
		}
		else{
			m2(a, b);
			if(good[getr(a)] || good[getr(b)])merge(a, b, w);
			else{
				deg[a]++; deg[b]++;
				if(max(deg[a], deg[b]) >= 3){
					good[getr(a)] = good[getr(b)] = 1;
					
					queue <int> q;
					q.push(getr(a));
					q.push(getr(b));
					merge(a, b, w);
					while(!q.empty()){
						int x = q.front(); q.pop();
						for(auto j : waiting[x]){
							if(!good[j]){
								good[j] = 1;
								merge(x, j, w);
								q.push(j);
							}
						}
						waiting[x].clear();
					}
				}
				else waiting[getr(a)].push_back(getr(b)), waiting[getr(b)].push_back(getr(a));
			}
		}
	}
	for(int i = cnt - 1; i >= N; i--)if(!dep[i])dfs(i, 1);
	for(int i = 1; i <= 19; i++)for(int j = 0; j < 2 * N; j++)up[i][j] = up[i - 1][up[i - 1][j]];
}
 
int getMinimumFuelCapacity(int X, int Y) {
  if(getr(X) != getr(Y))return -1;
  //cout << lca(X, Y) << ' ';
  return val[lca(X, Y)];
}

• Subtask 1: 6 / 6
• Subtask 2: 0 / 7
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27