README.md

Task 4c4377d9: Vertical Flip Concatenation

Pattern

Vertically flip the grid and concatenate with original.

Output = reversed rows + original rows

Algorithm

1. Reverse the row order of the input grid (g[::-1])
2. Concatenate with the original grid (+ g)

Solution (24 bytes)

solve=lambda g:g[::-1]+g

Key Tricks

Trick	Description	Savings
[::-1]	Python slice reversal - no function call needed	N/A
+	List concatenation - builds result directly	N/A
Lambda	Single expression, no return keyword	7 bytes

Byte History

Version	Bytes	Change
Initial lambda	24	solve=lambda g:g[::-1]+g

Why It's Short

This task has a nearly optimal solution:

• The operation is a single Python expression
• No per-element processing needed
• Slice reversal [::-1] is extremely concise
• List concatenation + is a single character

At 24 bytes, this is likely near the theoretical minimum for this task.