DEPTH-FIRST SEARCH

• Depth-first search explores a single path until its conclusion. If this path does not terminate on a goal state, we backtrack and arbitrarily continue with another path:
  
  Such a strategy is common for solving problems such as mazes where the first solution that reaches a goal state is acceptable (though this might not be the fastest solution).
  
  
• A general algorithm for searching such spaces can be defined as follows:
  
  
  
• Depth-first search, as we will see, is useful when dealing with beam search and fast-matching algorithms.