Cod sursa(job #1925574)

Utilizator 1475369147896537415369Andrei Udriste 1475369147896537415369 Data 13 martie 2017 13:41:56
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.65 kb
#include <cstdio>
#include <list>
#include <queue>
using namespace std;

struct edge{

    int v, weight;

    edge(int _v, int _w){
        v = _v;
        weight = _w;
    }
};

int vertices, edges, u, v, weight;
int dist[50001];
int visited[50001];
bool inQueue[50001];
const int infinity = 25000001;
list<edge> adj[50001];

bool BellmanFord(int source){

    for(int node = 1; node <= vertices; node++){
        dist[node] = infinity;
    }dist[source] = 0;

    queue<int> Q;
    Q.push(source);

    while(!Q.empty()){

        int u = Q.front(); Q.pop();
        inQueue[u] = false;

        for(list<edge>::iterator it = adj[u].begin(); it != adj[u].end(); it++){

            int v = it -> v;
            int weight = it -> weight;

            if(dist[v] > dist[u] + weight){

                dist[v] = dist[u] + weight;
                visited[v]++;

                if(inQueue[v] == false){
                    inQueue[v] = true;
                    Q.push(v);
                }
                if(visited[v] == vertices){
                    return false;
                }
            }
        }
    }
    return true;
}

int main(){

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

    scanf("%d %d", &vertices, &edges);

    for(int i = 1; i <= edges; i++){
        scanf("%d %d %d", &u, &v, &weight);
        adj[u].push_back(edge(v, weight));
    }
    if(BellmanFord(1) == false){
        printf("Ciclu negativ!");
        return 0;
    }
    for(int node = 2; node <= vertices; node++){
        printf("%d ", dist[node]);
    }
    return 0;
}