Cod sursa(job #3194051)

Utilizator Bianca2507Negret Bianca Bianca2507 Data 16 ianuarie 2024 19:16:24
Problema Radiatie Scor 80
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 2.14 kb
#include <fstream>
#include <algorithm>
#include <vector>
#include <climits>
using namespace std;
ifstream cin("radiatie.in");
ofstream cout("radiatie.out");
int n,k,m,t[15005],rad,viz[15005],nrm;
long long sol,d[15005];
pair<int,pair<int,int>>v[30005];
vector<pair<int,int>>apm[30005];
bool ok;
int radacina(int x)
{
    while(t[x]>0)
        x=t[x];
    return x;
}
void dfs(int nod,int nvl)
{
    viz[nod]=nvl;
    for(int i=0; i<apm[nod].size(); i++)
    {
        int vecin=apm[nod][i].first;
        int c=apm[nod][i].second;
        if(viz[vecin]==0)
        {
            t[vecin]=nod;
            d[vecin]=c;
            dfs(vecin,nvl+1);
        }
    }
    return ;
}
void lca(int x,int y)
{
    if(viz[x]<viz[y])
        swap(x,y);
    while(viz[x]>viz[y])
    {
        sol=max(sol,d[x]);
        x=t[x];
    }
    while(x!=y)
    {
        sol=max(sol,d[x]);
        sol=max(sol,d[y]);
        x=t[x];
        y=t[y];
    }
}
int main()
{
    cin>>n>>m>>k;
    ///seamana cu problema apm2 doar ca aici folosim lca
    for(int i=1; i<=m; i++)
    {
        cin>>v[i].second.first>>v[i].second.second>>v[i].first;
    }
    for(int i=1; i<=n; i++)
        t[i]=-1;
    sort(v+1,v+m+1);
    for(int i=1; i<=m&&ok==0; i++)
    {
        int rx=radacina(v[i].second.first);
        int ry=radacina(v[i].second.second);
        if(rx!=ry)
        {
            if(t[rx]<t[ry])
            {
                t[rx]+=t[ry];
                t[ry]=rx;
            }
            else
            {
                t[ry]+=t[rx];
                t[rx]=ry;
            }

            apm[v[i].second.first].push_back({v[i].second.second,v[i].first});
            apm[v[i].second.second].push_back({v[i].second.first,v[i].first});
            nrm++;
            if(nrm==n-1)
                ok=1;
        }
    }
    for(int i=1; i<=n; i++)
        if(t[i]<0)
        {
            rad=i;
            break;
        }
    t[rad]=0;
    dfs(rad,1);
    while(k--)
    {
        int a,b;
        cin>>a>>b;
        sol=LLONG_MIN;
        lca(a,b);
        cout<<sol<<'\n';
    }
    return 0;
}