Cod sursa(job #2856747)

Utilizator radugabriel16Magop Radu Gabriel radugabriel16 Data 24 februarie 2022 11:43:13
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.51 kb
#include <bits/stdc++.h>
#include <vector>
#include <queue>
#define NMAX 50002
#define INF 1000000000
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");

struct varf {
    int x;
    int cost;};
int n,x0=1,m;
vector<varf> G[NMAX]; ///lsite de adiacenta u costuri
bool uz[NMAX],rez;
int cmin[NMAX],pre[NMAX],nr[NMAX];
queue<int> C;
void afisare();
void citire();
bool bellmanford();
int main()
{
    citire();
    rez=bellmanford();
    afisare();
    return 0;
}
void citire(){
    int i,j,c;
    varf aux;
    fin>>n>>m;
    while(fin>>i>>j>>c){
        ///in lista de adiacenta a lui i trebuie sa adaug (j,c)
        aux.x=j;
        aux.cost=c;
        G[i].push_back(aux);
    }
    for(i=1;i<=n;i++) cmin[i]=INF;
    cmin[x0]=0;
}
bool bellmanford()///returneaza 0 daca exista circuite de cost negativ si 1 alfel
{
    ///initializez coada cu varful de start
    int x,vf,cost,i;
    C.push(x0); nr[x0]=1;
    while(!C.empty()){
        x=C.front(); C.pop();
        ///parcurg lista de adiacneta a lui x
        for(i=0;i<G[x].size();i++){
            vf=G[x][i].x; cost=G[x][i].cost;
            if(cmin[vf]>cmin[x]+cost){
                cmin[vf]=cmin[x]+cost;
                C.push(vf);
                nr[vf]++;
                if(nr[vf]==n) return 0;
            }
        }
    }
    return 1;
}
void afisare(){
    int i,j,afis[NMAX],cnt;
    if(rez==0) fout<<"Ciclu negativ!";
    else
    for(i=2;i<=n;i++) fout<<cmin[i]<<' ';

}