Cod sursa(job #2898311)

Utilizator teo1496Teodor Juravlea teo1496 Data 6 mai 2022 16:24:08
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
	
#include <bits/stdc++.h>
using namespace std;

ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
 
const int NMAX=50005;
const int INF=INT_MAX;
 
int n,m;
int d[NMAX],viz[NMAX];
bool incoada[NMAX];
 
vector <pair<int,int>> v[NMAX];
queue <int> Q;
 
bool Bellmanford(int start){
    for(int i=1;i<=n;i++){
        d[i]=INF;
        incoada[i]=0;
        viz[i]=0;
    }
    d[start]=0;
    Q.push(start);
    incoada[start]=true;
    while(!Q.empty()){
        int nodcurent = Q.front();
        viz[nodcurent]++;
        if(viz[nodcurent]>=n)
            return false;
        Q.pop();
        incoada[nodcurent]=false;
        for(unsigned int i=0;i<v[nodcurent].size();i++){
            int vecin=v[nodcurent][i].first;
            int cost=v[nodcurent][i].second;
            if(d[nodcurent]+cost<d[vecin]){
                d[vecin]=d[nodcurent]+cost;
                if(incoada[vecin]==false){
                    Q.push(vecin);
                    incoada[vecin]=true;
                }
            }
        }
    }
    return true;
}

int main(){
    fin>>n>>m;
    int x,y,c;
    for(int i=1;i<=m;i++){
        fin>>x>>y>>c;
        v[x].push_back(make_pair(y,c));
    }
    if(Bellmanford(1)){
        for(int i=2;i<=n;i++)
            fout<<d[i]<<" ";
    }
    else
        fout<<"Ciclu negativ!";
    return 0;
}