Initialize left at the start
Updated
Left is the start index. L ← 0. You compute it. You do not walk the array to discover the first slot.
What to focus on
L is 0 whenever n ≥ 1. L is not 1. Do not set L to n.
Worked examples
three
a = [4, 1, 9]- n = 3
- L ← 0
- a[0] = 4
Result: L=0
one
a = [7]- n = 1
- the only legal index is 0
Result: L=0
empty
a = []- n = 0
- index 0 does not exist
Result: no L
Try it
Write initLeft(a). a is an array of integers. L is the left index. Set L = 0. Print L. Return nothing. L must be 0 on every run. On [4, 1, 9], [4, 1, 9, 1], and [7], L is 0.
a may be empty. Length ≥ 1.