tree c01a94446dd343f14f3aab9fb13e1d2ed2b8df1b
parent db40fe78fefcfdeefb4ac4a94c72cfb20f40ee77
author Alberto Donizetti <alb.donizetti@gmail.com> 1559395699 +0200
committer Alberto Donizetti <alb.donizetti@gmail.com> 1560271551 +0000

tour: btrees do not store values just in leaves

The concurrency/7 slide (the binary tree exercise) says:

> There can be many different binary trees with the same sequence of
  values stored at the leaves.

Which is misleading: in the btree in the exercise, values are not
stored just in the leaves, the internal nodes hold values too.

Fixes golang/tour#774

Change-Id: I71af71ccf36ac8ad87dfe73b751b461890c3a7e0
Reviewed-on: https://go-review.googlesource.com/c/tour/+/179937
Reviewed-by: Andrew Bonventre <andybons@golang.org>