Cod sursa(job #1607082)

Utilizator king25Ionut Vasi king25 Data 20 februarie 2016 20:08:10
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.25 kb
#include <iostream>
#include <fstream>
#include <set>
#include <vector>
#define mp make_pair
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
vector<int> V[50001];
vector<int> C[50001];
int D[50001];
set < pair < int,int > > S;
int A[50001];
int n,m;
bool egata=false;
void dijkstra(int nod){
    S.insert(mp(0,nod));
    D[nod]=0;
    while(!S.empty()){
        int nod=(*S.begin()).second;
        A[nod]++;
        if(A[nod]==n){
            g<<"Ciclu negativ!";
            egata=true;
            return;
        }
        int dist=(*S.begin()).first;
        S.erase(S.begin());
        for(int i=0;i<V[nod].size();i++){
            if(D[V[nod][i]]>dist+C[nod][i]){
                D[V[nod][i]]=dist+C[nod][i];
                S.insert(mp(D[V[nod][i]],V[nod][i]));
            }
        }
    }
}
int main()
{
    f>>n>>m;
    int x,y,c;
    for(int i=0;i<m;i++){
        f>>x>>y>>c;
        V[x].push_back(y);
        C[x].push_back(c);
    }
    for(int i=1;i<=n;i++){
        D[i]=(1<<30)-1;
    }
    dijkstra(1);
    if(egata){
        return 0;
    }
    for(int i=2;i<=n;i++){
        if(D[i]==(1<<30)-1){
            g<<0<<" ";
        }else{g<<D[i]<<" ";}
    }
    return 0;
}