prev1 / prev2 [terminology]

Terminology¶

Usage¶

• Use for dynamic programming states one and two positions back.
• The suffix should describe distance from the current state:
  • prev1: one position back
  • prev2: two positions back
• Update them so their meaning remains stable after every iteration.
• Prefer more semantic names when the recurrence does not naturally use relative positions.

prev2, prev1 = 1, 1

for i in range(1, len(s)):
    cur = prev1
    prev2, prev1 = prev1, cur