Cod sursa(job #3032532)

Utilizator rARES_4Popa Rares rARES_4 Data 22 martie 2023 12:25:17
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.26 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream f ("bellmanford.in");
ofstream g ("bellmanford.out");
struct elem{
int nod,cost;
bool operator < (const elem &aux)
const{
        return aux.cost<cost;
    }
};
int dist[50001],fr[50001];
priority_queue < elem>q;
vector<pair<int,int>>adiacenta[50001];
int n,m;
int main()
{
    f >> n >> m;
    for(int i=1;i<=m;i++)
    {
        int x,y,c;
        f >> x >> y >> c;
        adiacenta[x].push_back({y,c});
    }

    for(int i = 1;i<=n;i++)
        dist[i]=(1<<30)-1;
    dist[1] = 0;
    q.push({1,0});
    while(!q.empty())
    {
        int curent = q.top().nod;
        int cost_curent = q.top().cost;
        q.pop();
        fr[curent]++;
        if(fr[curent]>n)
        {
            g << "Ciclu negativ!";
            return 0;
        }

        for(auto x:adiacenta[curent])
        {
            int nod_nou = x.first;
            int cost_nou = x.second;

            if(dist[nod_nou]>cost_curent+cost_nou)
            {
                dist[nod_nou]= cost_curent+cost_nou;
                q.push({nod_nou,dist[nod_nou]});
            }
        }

    }
    for(int i = 2;i<=n;i++)
        g << dist[i]<< " ";
}