Expand across the whole array
Updated
Expand until R = n-1. Every cell is included. Starting from L=0 R=-1, the window becomes the whole array: L=0, R=n-1.
What to focus on
After this, R cannot grow. The right edge is parked at the last index. Sum of the window equals sum of a.
Worked examples
three cells
a = [4, 1, 9], L=0 R=-1- R=0 include 4
- R=1 include 1
- R=2 include 9, R=n-1
Result: L=0 R=2 · [4, 1, 9]
four cells
a = [4, 1, 9, 1], L=0 R=-1- expand four times
- R stops at 3
Result: L=0 R=3 · [4, 1, 9, 1]
one cell
a = [7], L=0 R=-1- one expand
- R=0 = n-1
Result: L=0 R=0 · [7]
Try it
Write expandAll(a). a is an array of integers. Start from L=0, R=-1. Grow R until R = n-1. The window then includes every cell. Print (L, R) and prove R==n-1. Return nothing. On [4, 1, 9], [4, 1, 9, 1], and [7].
a is nonempty. Start from L=0, R=-1.