Cod sursa(job #1885946)

Utilizator leraValeria lera Data 20 februarie 2017 16:03:31
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define inf 999999999
#define Nmax 50005
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
vector<pair<int,int> >gr[Nmax];
queue<int>q;
int p,ok=1,dp[Nmax],cost[Nmax],n,m,x,y,c;
void parc(int nod)
{
    if(dp[nod]==n)
        ok=0;
    for(int i=0;i<gr[nod].size();i++)
        if(cost[nod]+gr[nod][i].second<cost[gr[nod][i].first])
        {
            dp[gr[nod][i].first]=dp[nod]+1;
            cost[gr[nod][i].first]=cost[nod]+gr[nod][i].second;
            q.push(gr[nod][i].first);
        }
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=n;i++)cost[i]=inf;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y>>c;
        gr[x].push_back(make_pair(y,c));
    }
    q.push(1);
    cost[1]=0;
    dp[1]=0;
    while(!q.empty() && ok==1)
    {
        p=q.front();
        parc(p);
        q.pop();
    }
    if(ok==0)fout<<"Ciclu negativ!";
    else for(int i=2;i<=n;i++)fout<<cost[i]<<" ";
    return 0;
}