Cod sursa(job #2196761)

Utilizator bogdanmarin69Bogdan Marin bogdanmarin69 Data 20 aprilie 2018 12:19:34
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.22 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream cin("dijkstra.in");
ofstream cout("dijkstra.out");
const int MAX = 50001, INF = (1 << 30);
vector<pair<int, int> > adj[MAX];
int n, m, d[MAX], p[MAX], ap[MAX];
int bellman(int s) {
    queue<int> q;
    for(int i = 1; i <= n; ++i) {
        d[i] = INF;
    }
    d[s] = 0;
    q.push(s);
    while(!q.empty()) {
        int u = q.front();
        q.pop();
        ++ap[u];
        if(ap[u] == n) {
            return 0;
        }
        for(auto it: adj[u]) {
            int v = it.first;
            int w = it.second;
            if(d[v] > d[u] + w) {
                d[v] = d[u] + w;
                p[v] = u;
                q.push(v);
            }
        }
    }
    for(int i = 1; i <= n; ++i) {
        if(d[i] == INF)
            d[i] = 0;
    }
    return 1;
}
int main()
{
    cin >> n >> m;
    for(int i = 1; i <= m; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back({v, w});
    }
    if(bellman(1) == 0) {
        cout << "Ciclu negativ!";
    } else {
        for(int i = 2; i <= n; ++i) {
            cout << d[i] << ' ';
        }
    }
    return 0;
}