Visualizing Backtracking

Here are some ways to visualize the backtracking algorithm:

Tree diagram:

Backtracking can be depicted as tree recursion. Each recursive call generates child subproblems. Backtracking occurs by returning to parent calls after exploring a branch.

For example, here is a tree for the N Queens problem, where each node represents trying a queen in a different column:

graph TD
A[Try col 1] --> B[Try col 2]
B --> C[Try col 3]
C --> D[Found solution]
C --> E[Try col 3 again] 
B --> F[Try col 2 again]

Pseudocode tracing:

Step through backtracking pseudocode iteratively showing the recursive calls and returns. For example:

explore(1)
  explore(2) 
    explore(3) - solution found!
    return
  explore(2) again
explore(1) again  

Visualizing the stack:

Show how the recursive calls form a stack that “unwinds” as solutions are found or branches are pruned.

These representations depict backtracking as systematically exploring a search space through tree recursion or stack operations. The key is illustrating recursive calls, backtracking, and pruning branches.

Place holder, refer the Mac Pro desktop and google doc notes