Cod sursa(job #1847736)

Utilizator msciSergiu Marin msci Data 14 ianuarie 2017 22:59:55
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp Status done
Runda Arhiva educationala Marime 1.14 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];
int n, m;

bool bellman_ford(int source) {
  dist[source] = 0;
  for (int k = 0; k < n - 1; k++) {
    for (int u = 0; u < n; u++) {
      for (pair<int, int>& e : g[u]) {
        int v = e.second, weight = e.first;
        if (dist[v] > dist[u] + weight) {
          dist[v] = dist[u] + weight;
        }
      }
    }
  }
  for (int u = 0; u < n; u++) {
    for (pair<int, int>& e : g[u]) {
      int v = e.second, weight = e.first;
      if (dist[v] > dist[u] + weight) {
        return false;
      }
    }
  }
  return true;
}

int main() {
  freopen("bellmanford.in", "r", stdin);
  freopen("bellmanford.out", "w", stdout);
  for (int i = 0; i < N; i++) {
    dist[i] = INF;
  }
  scanf("%d %d", &n, &m);
  for (int i = 0; i < m; i++) {
    int x, y, w;
    scanf("%d %d %d", &x, &y, &w);
    x--, y--;
    g[x].push_back({w, y});
  }
  bool ret = bellman_ford(0);
  if (!ret) {
    puts("Ciclu negativ!");
    return 0;
  }
  for (int i = 1; i < n; i++) {
    printf("%d ", dist[i]);
  }
  puts("");
  return 0;
}