R(n) | = | R(n-1) | + | n |
= | R(n-2) + n-1 | + | n | |
= | R(n-3) + n-2 + n-1 | + | n | |
... | ||||
= | R(0) + 1 + 2 + 3 + ... | + | n | |
= | n(n+1)/2 | (By Ex. 4.1) | ||
= | (n2+n)/2 (The number of conses to reverse a list of length n) | |||
= | Θ(n2) |
Since this version of reverse is inefficient, it is sometimes called naive reverse.