Cod sursa(job #3269766)

Utilizator DragosVNVisanescu Dragos Nicholas DragosVN Data 20 ianuarie 2025 17:17:07
Problema Algoritmul Bellman-Ford Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.26 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
int n,m;
const int inf=100000000;
typedef pair<int,int> pint;
vector<vector<pint>>G(50005);
vector <int> d(50005,inf);
bool inq[50005];
int l[50005];
void spfa(int start)
{
    queue <int>q;
    bool CN=0;
    d[start]=0;
    q.push(start);
    inq[start]=1;
    while(!q.empty()&&!CN)
    {
        int v=q.front();
        inq[v]=0;
        q.pop();
        for(int i=0;i<G[v].size()&&!CN;i++)
        {
            int u=G[v][i].second;
            if(!inq[u])
            {

                int w=G[v][i].first;
                if(d[u]>d[v]+w)
                {
                    l[u]=l[v]+1;
                    if(l[u]==n)
                    CN=1;
                    d[u]=d[v]+w;
                    q.push(u);
                    inq[u]=1;
                }
            }
        }
    }
    if(!CN)
    for(int i=2;i<=n;i++)
        g<<d[i]<<" ";
    else
        g<<"Ciclu negativ!";
}
int main()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y,c;
        f>>x>>y>>c;
        G[x].push_back(make_pair(c,y));
    }
    spfa(1);
    return 0;
}