Submission #533098

#	Time	Username	Problem	Language	Result	Execution time	Memory
533098		DanerZein	Road Closures (APIO21_roads)	C++14	0 / 100	2087 ms	18784 KiB

roads

#include "roads.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector<ii> vi;
typedef pair<ii,ll> iii;
const int MAX_N=2e5+10;
bool vis[MAX_N];
int pa[MAX_N];
vector<vi> G;
int n;
void init(int n){
  for(int i=0;i<n;i++)
    pa[i]=i;
}
int findset(int x){
  if(pa[x]==x) return x;
  return pa[x]=findset(pa[x]);
}
bool issameset(int i,int j){
  return findset(i)==findset(j);
}
void unionset(int i,int j){
  if(!issameset(i,j)){
    int u=findset(i),v=findset(j);
    pa[u]=v;
  }
}
ll dp[MAX_N];
int path[MAX_N];
ll knap(int u,int p){
  if(dp[u]!=-1) return dp[u];
  ll ans=0;
  for(auto &v:G[u]){
    if(v.first!=p){
      ans+=knap(v.first,u)+v.second;
    }
  }
  ll s=ans;
  int id=-1;
  for(auto &v:G[u]){
    if(v.first!=p){
      ll rp=s;
      rp=rp-dp[v.first]-v.second;
      for(auto &z:G[v.first]){
	if(z.first!=u){
	  rp+=dp[z.first]+z.second;
	}
      }
      if(ans>rp){
	ans=rp;
	id=v.first;
      }
    }
  }
  path[u]=id;
  return dp[u]=ans;
}
std::vector<long long> minimum_closure_costs(int N, std::vector<int> U,
                                             std::vector<int> V,
                                             std::vector<int> W) {
  n=N;
  vector<ll> res;
  vector<iii> ed;
  G.resize(n+1);
  ll s=0;
  for(int i=0;i<n-1;i++){
    int a=U[i],b=V[i],w=W[i];
    G[a].push_back(ii(b,w));
    G[b].push_back(ii(a,w));
    ed.push_back(iii(ii(a,b),w));
    s+=w;
  }
  res.push_back(s);
  init(n);
  for(int i=0;i<n-1;i++){
    memset(dp,-1,sizeof dp);
    res.push_back(knap(findset(0),findset(0)));
    for(int j=0;j<n;j++){
      if(path[j]!=-1) unionset(j,path[j]);
    }
    G.clear(); G.resize(n+1);
    for(int j=0;j<ed.size();j++){
      int u=findset(ed[j].first.first);
      int v=findset(ed[j].first.second);
      ll w=ed[j].second;
      if(u!=v){
	G[u].push_back(ii(v,w));
	G[v].push_back(ii(u,w));
      }
    }
  }
  return res;
}

Compilation message (stderr)

roads.cpp: In function 'std::vector<long long int> minimum_closure_costs(int, std::vector<int>, std::vector<int>, std::vector<int>)':
roads.cpp:84:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<long long int, long long int>, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |     for(int j=0;j<ed.size();j++){
      |                 ~^~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 7
• Subtask 3: 0 / 14
• Subtask 4: 0 / 10
• Subtask 5: 0 / 17
• Subtask 6: 0 / 25
• Subtask 7: 0 / 22