Cod sursa(job #2819255)

Utilizator Mirela_MagdalenaCatrina Mirela Mirela_Magdalena Data 18 decembrie 2021 10:34:57
Problema Algoritmul Bellman-Ford Scor 10
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.53 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#define MAX (1<<30)-1
#define NMAX 50005
using namespace std;
ifstream f ("bellmanford.in");
ofstream g ("bellmanford.out");
int intrari_in_queue[NMAX];
int cost[NMAX];
vector<pair<int,int>>adiacenta[NMAX];
queue<int>q;
int n,m;
void citire()
{
    f >> n >> m;
    for(int i = 1;i<=m;i++)
    {
        int x,y,c;
        f >> x >> y >> c;
        adiacenta[x].push_back({y,c});
    }
}
void init()
{
    for(int i = 1;i<=n;i++)
        cost[i] = MAX;
}
bool Bellman()
{
    q.push(1);
    cost[1] = 0;
    intrari_in_queue[1] = 1;
    while(!q.empty())
    {
        int nod_curent = q.front();
        int cost_curent = cost[nod_curent];
        q.pop();

        for(auto x:adiacenta[nod_curent])
        {
            int vecin = x.first;
            int cost_vecin = x.second;
            if(cost[vecin]>cost_curent+cost_vecin)
            {
                cost[vecin] = cost_curent+cost_vecin;
                q.push(vecin);
                intrari_in_queue[vecin]++;
            }
                if(intrari_in_queue[vecin]>=n)
                {
                    g<<"Ciclu negativ!";
                   return 1;
                }
        }
    }
}
void afisare()
{
    for (int i = 2; i <= n; i++)
	{
		if (cost[i] == MAX)
		{
			g << "0 ";
		}
		else
			g << cost[i] << " ";
	}
}
int main()
{
    citire();
    init();
    if(Bellman())
    {
        return 0;
    }
    afisare();
    return 0;
}