Cod sursa(job #1919183)

Utilizator delia_99Delia Draghici delia_99 Data 9 martie 2017 18:15:59
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.32 kb
#include <cstdio>
#include <vector>
#include <queue>
#include <cstdlib>
#define PII pair<int,int>

using namespace std;

const int NMAX=50000;
const int inf=2e9;

int n,m,i;
int nr[NMAX+5],D[NMAX+5];
bool used[NMAX+5];
vector <PII> G[NMAX+5];
queue <int> q;

void solve()
{
    int node,i,s,son,cost;
    q.push(1);

    while(!q.empty())
    {
        node=q.front();
        q.pop();
        used[node]=0;

        s=G[node].size();
        for(i=0; i<s; ++i)
        {
            son=G[node][i].first;
            cost=G[node][i].second;

            if(D[son]>D[node]+cost)
            {
                if(nr[son]==n-1)
                {
                    printf("Ciclu negativ!\n");
                    exit(0);
                }
                ++nr[son];
                D[son]=D[node]+cost;
                if(!used[son])
                    q.push(son);
            }
        }
    }
}

int main()
{
    freopen("bellmanford.in","r",stdin);
    freopen("bellmanford.out","w",stdout);

    scanf("%d%d",&n,&m);

    for(i=1; i<=m; ++i)
    {
        int x,y,c;
        scanf("%d%d%d",&x,&y,&c);
        G[x].push_back(make_pair(y,c));
    }

    for(i=2; i<=n; ++i)
        D[i]=inf;

    solve();

    for(i=2; i<=n; ++i)
        printf("%d ",D[i]);

    return 0;
}