Cod sursa(job #1537545)

Utilizator tudorcomanTudor Coman tudorcoman Data 27 noiembrie 2015 15:35:23
Problema Algoritmul lui Dijkstra Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb

#include <cstring>
#include <cstdio>
#include <vector>
#include <queue>
using namespace std;

const int maxN = 50000;
const int maxM = 250000;
const int infi = 1 << 30;
int N, M, d[maxN];

typedef pair<int, int> muchie; /// first = nodul, second = lungimea
priority_queue<muchie> H;
vector<muchie> G[maxN + 1];

void dijkstra() {
  for(register int i = 2; i <= N; ++ i)
    d[i] = infi;

  H.push(make_pair(1, 0));
  while(!H.empty()) {
    int length = H.top().second, nod = H.top().first;
    H.pop();
    for(auto it = G[nod].begin(); it != G[nod].end(); ++ it) {
      if(length + it->second < d[it->first]) {
        d[it->first] = length + it->second;
        H.push(make_pair(it->first, d[it->first]));
      }
    }
  }
  for(register int i = 2; i <= N; ++ i)
    if(d[i] == infi)
      d[i] = 0;
}

int main() {
  freopen("dijkstra.in", "r", stdin);
  freopen("dijkstra.out", "w", stdout);
  scanf("%d %d", &N, &M);
  for(register int i = 1; i <= M; ++ i) {
    int a, b, c;
    scanf("%d %d %d", &a, &b, &c);
    G[a].push_back(make_pair(b, c));
  }

  dijkstra();
  for(register int i = 2; i <= N; ++ i)
    printf("%d ", d[i]);
  printf("\n");
  return 0;
}