What is the difference between FIFO, LIFO, and Least Cost strategies in tree traversal?

Conditions

• Used for comparing different node exploration strategies in search trees.
• Applies to branch-and-bound search methods.

Reasoning, step by step

1. Identify the data structure used for node selection in each strategy.
2. FIFO uses a Queue (First-In-First-Out).
3. LIFO uses a Stack (Last-In-First-Out).
4. Least Cost uses a cost-based selection (Minimum Cost).
5. Compare the order in which nodes are chosen for expansion.

Example

The instructor summarizes, "FIFO method which one we select for exploration this one will expand. LIFO we try to expand this one. Least cost out of this whichever is having least cost we'll try that one."

Common misconceptions

• Confusing the data structure (queue/stack) with the expansion rule (breadth-first/depth-first) within a single node's children generation.
• Assuming Least Cost is the same as LIFO because both might seem to prioritize 'recent' or 'important' nodes without understanding the cost metric.

Watch the explanation

Explore next

• How does the Least Cost Branch and Bound algorithm decide which node to explore next?
• Why is Least Cost Branch and Bound considered more efficient than FIFO or LIFO?
• What is the difference between backtracking and branch and bound in this clip?