Question

Remarks: All the graphs here are without self loops and parallel edges, and anti-parallel edges. When we speak of a flow network, we mean there are capacities c(e) ? 0 on the edges, the graph G is directed with a source s and a destination t. In all the algorithms, always explain their correctness and analyze their complexity. The complexity should be as small as possible. A correct algorithm with large complexity, may not get full credit.

• Question 3: Given an undirected graph, give an algorithm that for every v returns the number of connected componnents in G ? v.

Answer 1

dfs(node u)
  for each node v connected to u :
    if v is not visited :
      visited[v] = true
      dfs(v)


for each node u:
  if u is not visited :
    visited[u] = true
    connected_component += 1
    dfs(u)