Cod sursa(job #2321113)

Utilizator AndreiDeltaBalanici Andrei Daniel AndreiDelta Data 15 ianuarie 2019 18:29:36
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.32 kb
#include <bits/stdc++.h>
#define Dim 50004
#define oo 250000008
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
int N,M,D[Dim],R[Dim],a,b,c;
bool viz[Dim];

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

vector < pair<int,int> > V[Dim];
priority_queue < int,vector<int>,cmp > minheap;

int main()
{
    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;
    D[1]=0;
    minheap.push(1);
    while(!minheap.empty())
    {
        int nod=minheap.top();
        minheap.pop();
        viz[nod]=0;
        R[nod]++;
        if(R[nod]==N)
        {
            g<<"Ciclu negativ!";
            return 0;
        }
        for(unsigned int i=0;i<V[nod].size();i++)
        {
            int vecin=V[nod][i].first;
            int cost=V[nod][i].second;
            if(D[nod]+cost<D[vecin])
            {
                D[vecin]=D[nod]+cost;
                if(!viz[vecin])
                {
                    minheap.push(vecin);
                    viz[vecin]=1;
                }
            }
        }
    }
    for(int i=2;i<=N;i++)
    if(D[i]==oo) g<<0<<" ";
    else g<<D[i]<<" ";
    return 0;
}