Submission #807278

#	Time	Username	Problem	Language	Result	Execution time	Memory
807278		hoangnghiep	Factories (JOI14_factories)	C++14	0 / 100	25 ms	24444 KiB

factories

#include<bits/stdc++.h>
#include "factories.h"
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#define ll long long
#define f first
#define s second
#define pii pair<int,ll>
#define piii pair<int,pair<int,int>>
#define vii vector<vector<int>>
#define vi vector<int>
#define cd complex<double>
#define endl '\n'
//#define multipletest
using namespace std;
const int LIM=5e5;
const ll INF=1e18;
const string name="template";
int n,m;
vector<pii> adj[LIM+5],adj_vt[LIM+5];
int time_dfs=0;
pii euler_tour[2*LIM+5],sparse_table[20][2*LIM+5];
int tin[LIM+5],tout[LIM+5],h[LIM+5];
ll dist_X[LIM+5],dist_Y[LIM+5],dist[LIM+5];
vector<int> List;
int color[LIM+5];
vector<int> st;
void dfs(int u,int parent,int depth){
 
	h[u] = depth;
	
	tin[u] = time_dfs;
	
	euler_tour[time_dfs++] = {depth,u};
	
	 
	for(auto v:adj[u]){
		if(v.f==parent) continue;
		dfs(v.f,u,depth + 1);
		
		euler_tour[time_dfs++] = {depth,u};
	    dist[v.f] = dist[u] + v.s;
	}
	tout[u] = time_dfs;
}
 
int lca(int u,int v){
	if(tin[u]>tin[v]){
		swap(u,v);
	}
	int bt = 31 - __builtin_clz(tin[v]-tin[u]+1);
	pii mn = min(sparse_table[bt][tin[u]],sparse_table[bt][tin[v] - (1<<bt) + 1]);
	return mn.s;
}
 
ll Dist(int u,int v){
	int LCA = lca(u,v);
	return dist[u] +  dist[v]- 2*dist[LCA];
} 
bool cmp(int a,int b){
	return tin[a]<tin[b];
}
 
bool isSubtree(int u,int v)
{
	return tin[u]<=tin[v] && tin[v]<=tout[u];
}
void dfs_to_find_sol(int u,int parent){
	for(auto v:adj_vt[u]){
		if(v.f==parent) continue;
		dfs_to_find_sol(v.f,u);
		dist_X[u] = min(dist_X[u],dist_X[v.f] + v.s);
		dist_Y[u] = min(dist_Y[u],dist_Y[v.f] + v.s);
	}
}
void Init(int N, int A[], int B[], int D[]){
	n=N;
	for(int i=0;i<n-1;++i){
		A[i]++;
		B[i]++;
	}
	for(int i=0;i<n-1;++i){
		adj[A[i]].push_back({B[i],D[i]});
		adj[B[i]].push_back({A[i],D[i]});
	}
	for(int i=1;i<=n;++i){
		dist_X[i]=INF;
		dist_Y[i]=INF;
		color[i] = -1;
	}
	
	dfs(1,0,0);
	
	for(int i=0;i<time_dfs;++i){
		sparse_table[0][i]  = euler_tour[i];
	}
	
 	for(int i=1;i<20;++i){
		for(int j=0;j+(1<<i)-1<time_dfs;++j){
			sparse_table[i][j] = min(sparse_table[i-1][j],sparse_table[i-1][j + (1<<(i-1))]);
		}
	}	
}
 
long long Query(int S, int X[], int T, int Y[]){
	for(auto x:List){
		color[x] = -1;
		adj_vt[x].clear();
		dist_X[x]=dist_Y[x]=INF;
	}
	List.clear();
	st.clear();
    for(int i=0;i<S;++i){
    	List.push_back(++X[i]);
    	color[X[i]] = 0;
    	dist_X[X[i]]=0;
    	dist_Y[X[i]]=INF;
	}
	for(int i=0;i<T;++i){
		List.push_back(++Y[i]);
		if(color[Y[i]]==0){
			return 0;
		}
		color[Y[i]]=1;
		dist_X[Y[i]]=INF;
		dist_Y[Y[i]]=0;
	}
		
	sort(List.begin(),List.end(),cmp);
	for(int i=1;i<S+T;++i){
		int LCA = lca(List[i-1],List[i]);
		if(color[LCA]==-1){
			dist_X[LCA] = dist_Y[LCA]  =  INF;
		}
		List.push_back(LCA);
	}
	
	int root;
	sort(List.begin(),List.end(),cmp);
	List.erase(unique(List.begin(),List.end()),List.end());
	for(int i=0;i<List.size();++i){
		int u = List[i];
		while(st.size()>=2 && !isSubtree(st.back(),u)){
			int x = st[st.size()-2];
			int y= st.back();
			ll w=Dist(x,y);
			adj_vt[x].push_back({y,w});
			adj_vt[y].push_back({x,w});
			root=x;
			st.pop_back();
		}
		st.push_back(u);
	}
	while(st.size()>=2){
			int x = st[st.size()-2];
			int y= st.back();
			ll w=Dist(x,y);
			adj_vt[x].push_back({y,w});
			adj_vt[y].push_back({x,w});
			root=x;
			st.pop_back();
	}
	dfs_to_find_sol(root,0);
	ll ans=INF;
    for(auto x:List){
    	ans = min(ans,dist_X[x] + dist_Y[x]);
	}
   	return ans;
}

Compilation message (stderr)

factories.cpp: In function 'long long int Query(int, int*, int, int*)':
factories.cpp:141:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  141 |  for(int i=0;i<List.size();++i){
      |              ~^~~~~~~~~~~~
factories.cpp:163:17: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
  163 |  dfs_to_find_sol(root,0);
      |  ~~~~~~~~~~~~~~~^~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 18
• Subtask 3: 0 / 67