Cod sursa(job #2844930)

Utilizator VipioanaMirea Oana Teodora Vipioana Data 6 februarie 2022 12:54:16
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
const int N=5e4+1;
const int INF=2e9;
int n,m;
int cont[N];
vector <int> d(N,INF);
vector <pair<int,int>> a[N];
bool inQueue[N];

bool BellmanFord(){
    queue <int> q;
    q.push(1);
    d[1]=0;
    cont[1]=inQueue[1]=1;
    while(!q.empty()){
        int x=q.front();
        q.pop();
        inQueue[x]=0;
        for(auto j:a[x]){
            if(d[x]+j.second<d[j.first]){
                d[j.first]=d[x]+j.second;
                if(!inQueue[j.first]){
                    q.push(j.first);
                    inQueue[j.first]=1;
                    cont[j.first]++;
                    if(cont[j.first]==n)
                        return 0;
                }
            }
        }
    }
    return 1;
}

int main()
{
    f>>n>>m;
    for(int i=1; i<=m; i++){
        int x,y,c;
        f>>x>>y>>c;
        a[x].push_back({y,c});
    }
    if(!BellmanFord())
        g<<"Ciclu negativ!";
    else{
        for(int i=2; i<=n; i++)
            g<<d[i]<<" ";
    }
    return 0;
}