Cod sursa(job #2594935)

Utilizator AndreiDeltaBalanici Andrei Daniel AndreiDelta Data 6 aprilie 2020 19:52:52
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 2.11 kb
#include <bits/stdc++.h>
#define Dim 50002
#define oo 1e9
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
int N,M,D[Dim],T[Dim];
bool viz[Dim];

vector < pair<int,int> > V[Dim];

void Path(int u)
{
    vector < int > way;
    while(u!=0)
    {
        way.push_back(u);
        u=T[u];
    }
    for(int i=way.size()-1;i>=0;i--) cout<<way[i]<<' ';
    cout<<'\n';
}

struct cmp
{
    bool operator ()(int x,int y)
    {
        if( D[x] < D[y] ) return 1;
        else
        if(D[x]==D[y])
        {
            if(x<y) return 1;
            else return 0;
        }
        else return 0;
    }
};

set < int,cmp > S;
set < int,cmp > :: iterator it,it_find;


void Dijkstra()
{
    D[1]=0;
    S.insert(1);

    while( !S.empty() )
    {
        int nod=*S.begin();
        S.erase(S.begin());

        for(unsigned int i=0;i<V[nod].size();i++)
        {
            int vecin=V[nod][i].first;
            int cost=V[nod][i].second;
            if( D[vecin] > D[nod] + cost )
            {
                if( D[vecin] != oo ) S.erase( S.find(vecin) );
                D[vecin]=D[nod]+cost;
                S.insert(vecin);
            }
        }
    }
}

int main()
{
    int a,b,c;
    f>>N>>M;
    for(int i=1;i<=M;i++)
    {
        f>>a>>b>>c;;
        V[a].push_back({b,c});
    }

    for(int i=1;i<=N;i++) D[i]=oo;
    Dijkstra();

    /*D[1]=0;
    T[1]=0;
    for(int i=1;i<=N;i++)
    {
        int minim=oo;
        int idx_nod;

        for(int j=1;j<=N;j++)
        if(!viz[j] && D[j]<minim )
        {
            minim=D[j];
            idx_nod=j;
        }

        viz[idx_nod]=1;
        for(unsigned int i=0;i<V[idx_nod].size();i++)
        {
            int vecin =V[idx_nod][i].first;
            int cost =V[idx_nod][i].second;
            if( D[vecin] > D[idx_nod] +  cost)
            {
                D[vecin]=D[idx_nod]+cost;
                T[vecin]=idx_nod;
            }
        }
    }*/

    for(int i=2;i<=N;i++)
    if(D[i]!=oo)g<<D[i]<<' ';
    else g<<0<<' ';

    return 0;
}