title: What is a fast algorithm for finding critical nodes?
body: <p>I'm looking for a quick method/algorithm for finding which nodes in a graph is critical.</p>
  
  <p>For example, in this graph:
  <img src="https://i.stack.imgur.com/1reXa.png" alt="alt text"></p>
  
  <p>Node number 2 and 5 are critical.</p>
  
  <p>My current method is to try removing one non-endpoint node from the graph at a time and then check if the entire network can be reached from all other nodes. This method is obvious not very efficient.</p>
  
  <p>What are a better way?</p>