Cod sursa(job #1817640)

Utilizator MithrilBratu Andrei Mithril Data 28 noiembrie 2016 10:47:49
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp Status done
Runda Arhiva educationala Marime 1.43 kb
#include <bits/stdc++.h>
using namespace std;

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

struct Muchie{int nodAdiacent,costMuchie;};
int n,m,x,y,z,top;
vector<long> dist;
vector<bool> inQueue;
queue<int> Q;
vector<Muchie> adj[50001];

bool cicluNegativ()
{
    for(int i=1;i<=n;i+=1)
        for(vector<Muchie>::iterator j=adj[top].begin();j!=adj[top].end();j++)
            if(dist[j->nodAdiacent]>dist[i]+j->costMuchie)
                return true;
    return false;
}

int main()
{
    fin>>n>>m;
    dist.resize(n+1,LONG_MAX);
    inQueue.resize(n+1);
    for(int i=0;i<m;i+=1)
    {
        fin>>x>>y>>z;
        adj[x].push_back({y,z});
    }
    Q.push(1);
    dist[1]=0;
    inQueue[1]=true;
    for(int i=0;Q.size()&&i<=1LL*n*m;i+=1)
    {
        top=Q.front();
        Q.pop();
        inQueue[top]=false;
        for(vector<Muchie>::iterator it=adj[top].begin();it!=adj[top].end();it++)
            if(dist[it->nodAdiacent]>dist[top]+it->costMuchie)
            {
                dist[it->nodAdiacent]=dist[top]+it->costMuchie;
                if(!inQueue[it->nodAdiacent])
                {
                    Q.push(it->nodAdiacent);
                    inQueue[it->nodAdiacent]=true;
                }
            }
    }
    if(cicluNegativ())
    {
        fout<<"Ciclu negativ!";
        return 0;
    }
    for(int i=2;i<=n;i+=1)fout<<dist[i]<<' ';
    return 0;
}