Cod sursa(job #1849948)

Utilizator OlivianOlivian Dan Cretu Olivian Data 17 ianuarie 2017 23:21:01
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.26 kb
#include <cstdio>
#include <vector>
#include <queue>
using namespace std;
const int inf=1000000000;
struct edge
{
    int nod,c;
};
vector<edge> v[50010];
queue<int> q;
int d[50010],cnt[50010],n;
char introdus[50010];

int bellman_ford(int nod)
{
    for(int i=1; i<=n; i++) d[i]=inf;
    d[nod]=0;
    q.push(nod);
    introdus[nod]=1;
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        introdus[nod]=0;
        for(vector<edge>::iterator it=v[nod].begin(); it!=v[nod].end(); it++)
            if(d[it->nod]>d[nod]+it->c)
            {
                d[it->nod]=d[nod]+it->c;
                if(!introdus[it->nod])
                {
                    if(++cnt[it->nod]==n) return 0;
                    q.push(it->nod);
                    introdus[it->nod]=1;
                }
            }
    }
    return 1;
}
int main()
{
    freopen("bellmanford.in", "r", stdin);
    freopen("bellmanford.out", "w", stdout);
    int m,x,y,c;
    scanf("%d%d",&n,&m);
    for(int i=1; i<=m; i++)
    {
        scanf("%d%d%d",&x,&y,&c);
        v[x].push_back({y,c});
    }
    if(!bellman_ford(1)) printf("Ciclu negativ!");
    else
    {
        for(int i=2; i<=n; i++) printf("%d ",d[i]);
    }
    return 0;
}