Cod sursa(job #2354209)

Utilizator HelloWorldBogdan Rizescu HelloWorld Data 25 februarie 2019 00:34:32
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.25 kb
#include <fstream>
#include <vector>
#include <queue>
#include <bitset>
#include <limits.h>
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");
int n,m,x,y,c,i,d[50001],viz[50001];
vector <pair<int,int>> a[50001];
queue <int> Q;
bitset <50001> in_queue;
int bellman()
{
    Q.push(1);
    d[1]=0;
    in_queue[1]=1;
    while (!Q.empty())
    {
        int x=Q.front();
        viz[x]++;
        if (viz[x]==n)
            return 1;
        for (int i=0; i<a[x].size(); ++i)
        {
            int vecin=a[x][i].first;
            int cost=a[x][i].second;
            if (cost+d[x]<d[vecin])
            {
                d[vecin]=cost+d[x];
                if (!in_queue[vecin])
                {
                    in_queue[vecin]=1;
                    Q.push(vecin);
                }
            }
        }
        in_queue[x]=0;
        Q.pop();
    }
    return 0;
}
int main()
{
    in>>n>>m;
    for (i=1; i<=m; ++i)
    {
        in>>x>>y>>c;
        a[x].push_back({y,c});
    }
    for (i=1;i<=n;++i)
         d[i]=INT_MAX;
    if (bellman())
        out<<"Ciclu negativ!";
    else
    {
        for (i=2; i<=n; ++i)
            out<<d[i]<<" ";
        out<<"\n";
    }
}