Cod sursa(job #1468925)

Utilizator horiainfoTurcuman Horia horiainfo Data 7 august 2015 12:24:39
Problema Algoritmul Bellman-Ford Scor 55
Compilator cpp Status done
Runda Arhiva educationala Marime 1.2 kb
#include <fstream>
#include <queue>
#include <vector>
#include <cstdlib>
#include <memory.h>

#define INF 0x3f3f3f3f
#define NMAX 50002
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
int cost[NMAX],n,m,x,y,c;
struct elem{vector<int> vecin,cost;} G[NMAX];

void BFS()
{
    int nod;
    queue<int> co;
    co.push(1);
    cost[1]=0;
    while(!co.empty())
    {
        nod = co.front();
        co.pop();
        for(int i=0;i<G[nod].vecin.size();i++)
            if(cost[nod]+G[nod].cost[i] + cost[G[nod].vecin[i]] < 0)
            {
                fout<<"Ciclu negativ!";
                exit(0);
            }
            else
                if(cost[nod]+G[nod].cost[i] < cost[G[nod].vecin[i]])
                {
                    cost[G[nod].vecin[i]] = cost[nod]+G[nod].cost[i];
                    co.push(G[nod].vecin[i]);
                }
    }
}

int main()
{
    fin>>n>>m;

    memset(cost,INF,sizeof(cost));

    for(int i=1;i<=m;i++)
    {
        fin>>x>>y>>c;
        G[x].vecin.push_back(y);
        G[x].cost.push_back(c);
    }

    BFS();

    for(int i=2;i<=n;i++)
        fout<<cost[i]<<' ';
    return 0;
}