Cod sursa(job #1114103)

Utilizator MarghescuGabriel Marghescu Marghescu Data 21 februarie 2014 11:48:54
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
#include <fstream>
#define nmax   50003
#define inf 0x3f3f3f3f
#include<queue>
#include<vector>
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
int n,m,cost[nmax],nr[250003];
vector <int> v[nmax];
queue <int> q;
int solve()
{
    q.push(1);
    while(!q.empty())
    {
        int x=q.front();
        for(int i=0;i<v[x].size();i+=2)
        {
            if(cost[v[x][i]]>cost[x]+v[x][i+1])
            {
                q.push(v[x][i]);
                cost[v[x][i]]=cost[x]+v[x][i+1];
                ++nr[v[x][i]];
            }
            if(nr[v[x][i]]>=n)
                return 0;
        }
        q.pop();
    }
    return 1;
}
int main()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int a,b,c;
        f>>a>>b>>c;
        v[a].push_back(b);
        v[a].push_back(c);
    }
    for(int i=2;i<=n;i++)
        cost[i]=inf;
    if(solve())
    {
        for(int i=2;i<=n;i++)
            g<<cost[i]<<" ";
    }
    else
    {
        g<<"Ciclu negativ!";
    }
    return 0;
}