Cod sursa(job #2838441)

Utilizator TudosieRazvanTudosie Marius-Razvan TudosieRazvan Data 23 ianuarie 2022 17:09:42
Problema Radiatie Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 2.38 kb
#include <fstream>
#include <vector>
#include <algorithm>
#define NMAX 15003
using namespace std;

ifstream fin ("radiatie.in");
ofstream fout ("radiatie.out");

int n,m,k;
struct muchie
{
    int x,y,cost;
};
vector<muchie> v;
vector<int>graf[NMAX];
int tata[NMAX];
int cost[NMAX],rad;
bool viz[NMAX];
int nivel[NMAX];

bool cmp(muchie a,muchie b)
{
    return a.cost<b.cost;
}

int cRad(int val)
{
    int rad=val;
    while(tata[rad]>0)
    {
        rad=tata[rad];
    }
    return rad;
}

void kruskal()
{
    stable_sort(v.begin(),v.end(),cmp);

    int k=0;
    for(int i=0; i<v.size() && k<n; i++)
    {
        int rad1=cRad(v[i].x);
        int rad2=cRad(v[i].y);
        if(rad1!=rad2)
        {
            k++;
            //unesc arborii
            if(tata[rad1]<=tata[rad2])
            {
                tata[rad1]+=tata[rad2];
                tata[rad2]=rad1;

                //compresie
                graf[rad1].push_back(rad2);
                cost[rad2]=v[i].cost;

                rad=rad1;
            }
            else
            {
                tata[rad2]+=tata[rad1];
                tata[rad1]=rad2;
                rad=rad2;


                graf[rad2].push_back(rad1);
                cost[rad1]=v[i].cost;
            }
        }
    }
}

void dfs(int nod)
{
    viz[nod]=true;
    for(int i=0; i<graf[nod].size(); i++)
    {
        int nd=graf[nod][i];
        if(!viz[nd])
        {
            nivel[nd]=nivel[nod]+1;
            dfs(nd);
        }
    }
}

int main()
{
    fin>>n>>m>>k;
    for(int i=1; i<=m; i++)
    {
        int x,y,z;
        fin>>x>>y>>z;
        v.push_back( {x,y,z});
    }
    //aplic kruskal
    for(int i=1; i<=n; i++)
    {
        tata[i]=-1;
    }
    kruskal();

    nivel[rad]=1;
    dfs(rad);
    for(int i=1; i<=k; i++)
    {
        int x,y;
        fin>>x>>y;
        int maxim=0;

        while(nivel[x]>nivel[y])
        {
            maxim=max(maxim,cost[x]);
            x=tata[x];

        }
        while(nivel[y]>nivel[x])
        {
             maxim=max(maxim,cost[y]);
            y=tata[y];
        }
        while(x!=y)
        {
            maxim=max(maxim,cost[x]);
            maxim=max(maxim,cost[y]);
            x=tata[x];
            y=tata[y];

        }
        fout<<maxim<<"\n";
    }
    return 0;
}