Cod sursa(job #2565444)

Utilizator denmirceaBrasoveanu Mircea denmircea Data 2 martie 2020 14:14:43
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.09 kb
#include <bits/stdc++.h>
#define inf 2000000000
#define dim 50005
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
deque<int> q;
vector <pair<int,int> > L[dim];
int n,m,d[dim],x,y,z;
bitset<dim> iq;
int fr[dim];
int bf(int nod){
    int i;
    q.push_back(nod);
    for(i=1;i<=n;i++)
        d[i]=inf;
    d[1]=0;
    while(!q.empty()){
        nod=q.front();
        q.pop_front();
        iq[nod]=0;
        fr[nod]++;
        if(fr[nod]==n)
            return -1;
        for(auto it:L[nod]){
            int v=it.first;
            int c=it.second;
            if(d[v]>d[nod]+c){
                d[v]=d[nod]+c;
                if(iq[v]==0){
                    q.push_back(v);
                }
                iq[v]=1;
            }
        }
    }
    return 0;
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++){
        fin>>x>>y>>z;
        L[x].push_back({y,z});
    }
    int val=bf(1);
    if(val==-1){
        fout<<"Ciclu negativ!";
        return 0;
    }
    for(int i=2;i<=n;i++)
        fout<<d[i]<<" ";
}