# Exercise 14.1.2

Show how $\text{OS-RANK}(T, x)$ operates on the red-black tree $T$ of Figure 14.1 and the node $x$ with $x.key = 35$.

It does the following:

starts with

y.key = 35
r = 1

then goes in the while loop:
1. y.key = 35; r = 1; goes up, adds nothing
2. y.key = 38; r = 1; goes up, adds rank of left sibling plus one
3. y.key = 30; r = 3; goes up, adds nothing
4. y.key = 41; r = 3; goes up, adds rank of left sibling plus one
5. y.key = 20; r = 16; returns 16