B-Tree Deletion with Rebalancing

Write a C program that implements B-tree deletion with rebalancing.

Requirements:

• Use MAX_KEYS=3, MIN_KEYS=1
• Implement btree_delete(root, key) that removes a key and rebalances
• Implement helper functions:
  • borrow_from_left(node, parent_index): redistribute with left sibling
  • borrow_from_right(node, parent_index): redistribute with right sibling
  • merge_with_sibling(node, parent_index): merge with a sibling
• Start with a pre-built tree: Root: keys=[20], children=[left, right] left: keys=[5, 10, 15], is_leaf=1 right: keys=[25, 30, 35], is_leaf=1
• Delete 5 (simple, leaf has > MIN_KEYS)
• Delete 15 (leaf drops to MIN_KEYS, borrow from right sibling or merge)
• Delete 20 (internal node, replace with predecessor or successor)
• After each deletion, print the tree structure
• Verify that no node has fewer than MIN_KEYS keys
• Count and print the number of redistribution and merge operations performed