Submission #708665

#	Time	Username	Problem	Language	Result	Execution time	Memory
708665		ToroTN	Factories (JOI14_factories)	C++14	33 / 100	8055 ms	236768 KiB

factories

#include "factories.h"
#include<bits/stdc++.h>
using namespace std;
//#include "grader.cpp"
#define ll long long
#define pb push_back
#define X first
#define Y second
const int maxmum=500005,maxlift=25;
vector<pair<int,int> > v[maxmum];
int n,lv[maxmum],par[maxmum][maxlift];
ll d[maxmum];
void dfs(int u,int p)
{
    for(int i=0;i<v[u].size();i++)
    {
        int node=v[u][i].X,cost=v[u][i].Y;
        if(node==p)continue;
        lv[node]=lv[u]+1;
        d[node]=d[u]+cost;
        par[node][0]=u;
        dfs(node,u);
    }
}
int lca(int a,int b)
{
    if(lv[a]<lv[b])swap(a,b);
    for(int i=19;i>=0;i--)
    {
        if(lv[par[a][i]]>=lv[b])
        {
            a=par[a][i];
        }
    }
    if(a==b)return a;
    for(int i=19;i>=0;i--)
    {
        if(par[a][i]!=par[b][i])
        {
            a=par[a][i],b=par[b][i];
        }
    }
    return par[a][0];
}
ll lca_dis(int a,int b)
{
    return d[a]+d[b]-2*d[lca(a,b)];
}
int sz[maxmum],vis[maxmum],par_cen[maxmum];
ll opt[maxmum][maxlift];
int dfs_sz(int u,int p)
{
    sz[u]=1;
    for(int i=0;i<v[u].size();i++)
    {
        int node=v[u][i].X;
        if(node==p||vis[node])continue;
        sz[u]+=dfs_sz(node,u);
    }
    return sz[u];
}
int find_cen(int u,int p,int size)
{
    for(int i=0;i<v[u].size();i++)
    {
        int node=v[u][i].X;
        if(node==p||vis[node])continue;
        if(sz[node]>size/2)return find_cen(node,u,size);
    }
    return u;
}
void centroid(int u,int p)
{
    dfs_sz(u,u);
    int cen=find_cen(u,u,sz[u]);
    vis[cen]=1;
    par_cen[cen]=p;
    for(int i=0;i<v[cen].size();i++)
    {
        ll node=v[cen][i].X;
        if(node==p||vis[node])continue;
        centroid(node,cen);
    }
}
ll mn[maxmum];
void Init(int N, int A[], int B[], int D[]) 
{
    n=N;
    for(int i=0;i<n-1;i++)
    {
        v[A[i]+1].pb({B[i]+1,D[i]});
        v[B[i]+1].pb({A[i]+1,D[i]});
    }
    par[1][0]=1;
    dfs(1,1);
    for(int i=1;i<=19;i++)
    {
        for(int j=1;j<=n;j++)
        {
            par[j][i]=par[par[j][i-1]][i-1];
        }
    }
    dfs_sz(1,1);
    centroid(1,0);
    for(int i=1;i<=n;i++)
    {
        ll x=i,kk=0;
        while(1)
        {
            opt[i][kk]=lca_dis(x,i);
            ++kk;
            x=par_cen[x];
            if(x==0)break;
        }
    }
    for(int i=1;i<=n;i++)mn[i]=1e18;
}
void update(int num,int type)
{
    int u=num,kk=0;
    while(1)
    {
        if(type==0)
        {
            mn[u]=min(mn[u],opt[num][kk]);
        }else
        {
            mn[u]=1e18;
        }
        u=par_cen[u];
        ++kk;
        if(u==0)break;
    }
}
ll query(ll num)
{
    int u=num,kk=0;
    ll val=1e18;
    while(1)
    {
        val=min(val,opt[num][kk]+mn[u]);
        u=par_cen[u];
        ++kk;
        if(u==0)break;
    }
    return val;
}
long long Query(int S, int X[], int T, int Y[]) 
{
    for(int i=0;i<S;i++)
    {
        update(X[i]+1,0);
    }
    ll ans=1e18;
    for(int i=0;i<T;i++)
    {
        ans=min(ans,query(Y[i]+1));
    }
    for(int i=0;i<S;i++)
    {
        update(X[i]+1,1);
    }
    return ans;
}

Compilation message (stderr)

factories.cpp: In function 'void dfs(int, int)':
factories.cpp:15:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |     for(int i=0;i<v[u].size();i++)
      |                 ~^~~~~~~~~~~~
factories.cpp: In function 'int dfs_sz(int, int)':
factories.cpp:54:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |     for(int i=0;i<v[u].size();i++)
      |                 ~^~~~~~~~~~~~
factories.cpp: In function 'int find_cen(int, int, int)':
factories.cpp:64:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |     for(int i=0;i<v[u].size();i++)
      |                 ~^~~~~~~~~~~~
factories.cpp: In function 'void centroid(int, int)':
factories.cpp:78:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |     for(int i=0;i<v[cen].size();i++)
      |                 ~^~~~~~~~~~~~~~

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