Flush a Memtable to Disk as an SSTable

Write a C program that flushes a sorted memtable to a simple SSTable format.

Requirements:

• Define a memtable as a sorted array of key-value pairs
• Implement flush_memtable() that writes:
  • A header: "SSTABLE v1 "
  • Data section: each key-value pair as "key=value "
  • Index section: "INDEX " followed by every 3rd key and its line offset
  • Footer: "EOF "
• Use this memtable data: (1,10), (2,20), (3,30), (5,50), (7,70), (8,80), (10,100), (12,120)
• Print the complete SSTable to stdout
• Implement sstable_find() that reads the index, locates the approximate block, and scans for the key
• Search for keys: 5, 8, 15 (not found)
• Print the index entries and their offsets
• Calculate and print the compression ratio if keys were stored with prefix compression (compare full keys vs deltas)
• Include a note about why SSTables are immutable