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.

prev1, prev2 = 1, 2
for _ in range(n - 2):
    prev1, prev2 = prev2, prev1 + prev2

See 70. Climbing Stairs.