A binary search tree stores nodes with at most two child branches. Ordering places smaller elements on the left and larger elements on the right, allowing searches to discard half the tree at each step. section 7.2.1
Searching map keys
A map can store {1:a}, {3:c}, and {5:e} in a balanced binary search tree. Searching for {2:b} starts at {3:c}, moves left to {1:a}, and stops at the leaf. Balanced search, insertion, and removal take logarithmic complexity, O(log(n)). section 7.2.1
Figure 7.2 Three elements in a balanced binary search tree: nodes with smaller keys go on the left and larger keys on the right.
Use the tree diagram to see how smaller keys occupy the left side and larger keys occupy the right side. section 7.2.1




