Cod sursa(job #1847603)

Utilizator msciSergiu Marin msci Data 14 ianuarie 2017 19:42:35
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <bits/stdc++.h>

using namespace std;

const int N = 50005;
const int INF = 0x3f3f3f3f;

vector< pair<int, int> > g[N];
int dist[N];

void dijkstra(int source) {
  dist[source] = 0;
  set< pair<int, int> > q;
  q.insert({dist[source], source});
  while (!q.empty()) {
    int u = q.begin()->second, dist_u = q.begin()->first;
    q.erase(q.begin());
    if (dist[u] < dist_u) {
      continue;
    }
    for (pair<int, int>& e : g[u]) {
      int v = e.second, weight_uv = e.first;
      if (dist[v] > dist[u] + weight_uv) {
        dist[v] = dist[u] + weight_uv;
        q.insert({dist[v], v});
      }
    }
  }
}

int main() {
  freopen("dijkstra.in", "r", stdin);
  freopen("dijkstra.out", "w", stdout);
  for (int i = 0; i < N; i++) {
    dist[i] = INF;
  }
  int n, m;
  scanf("%d %d", &n, &m);
  for (int i = 0; i < m; i++) {
    int x, y, w;
    scanf("%d %d %d", &x, &y, &w);
    g[x].push_back({w, y});
  }
  dijkstra(1);
  for (int i = 2; i <= n; i++) {
    printf("%d ", (dist[i] == INF ? 0 : dist[i]));
  }
  puts("");
  return 0;
}