Function optimal_leaf_ordering 

pub fn optimal_leaf_ordering<F: Float + FromPrimitive + PartialOrd + Debug>(
    z: &Array2<F>,
    d: &Array1<F>,
) -> Result<Array1<usize>>

Calculates the optimal leaf ordering for a dendrogram

This reorders the leaves to minimize the sum of distances between adjacent leaves. Uses automatic algorithm selection: exact for small dendrograms, heuristic for large ones.

Arguments

• z - The linkage matrix
• d - The original distance matrix (condensed form)

Returns

• Result<Array1<usize>> - The optimal leaf ordering