Cod sursa(job #2196757)

Utilizator bogdanmarin69Bogdan Marin bogdanmarin69 Data 20 aprilie 2018 12:13:16
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.65 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);
int n, d[MAX], m, sel[MAX];
vector<pair<int, int> > adj[MAX];
class mycomparison
{
public:
  bool operator() (const pair<int, int> &lhs, const pair<int, int> &rhs) const
  {
    return (lhs.second > rhs.second);
  }
};
void dijkstra(int s) {
    for(int i = 1; i <= n; ++i) {
        d[i] = INF;
    }
    d[s] = 0;
    priority_queue<pair<int, int>, vector<pair<int, int> >, mycomparison> pq;
    pq.push({s, d[s]});
    while(!pq.empty()) {
        int u = pq.top().first;
        int dist = pq.top().second;
        pq.pop();
        if(dist > d[u]) continue;
        for(auto it: adj[u]) {
            int v = it.first;
            int w = it.second;
            if(sel[v] == 0 && d[v] > d[u] + w) {
                d[v] = d[u] + w;
                pq.push({v, d[v]});
            }
        }
    }
    for(int i = 1; i <= n; ++i) {
        if(d[i] == INF)
            d[i] = 0;
    }
}
int main()
{
    /*
    ifstream f1("dijkstra.out");
    ifstream f2("out.ok");
    ofstream cout("debug.out");
    for(int i = 1; i <= 50000; ++i) {
        int x, y;
        f1 >> x; f2 >> y;
        if(x != y) {
            cout << i << ' ' << x << ' ' << y << endl;
        }
    }
    return 0;
    */
    cin >> n >> m;
    for(int i = 1; i <= m; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back({v, w});
    }
    dijkstra(1);
    for(int i = 2; i <= n; ++i) {
        cout << d[i] << ' ';
    }

    return 0;
}