In the fourth edition of Sedgewick's Algorithms, it's claimed that the running time of QuickSort is $\sim 1.39n\log_2 n$. I'm trying to find a simple proof and explanation of this.All I know is that the total running time obeys $$C_n = C_{\mathrm{partitioning}} + C_{\mathrm{leftArray}} + C_{\mathrm{rightarray}}$$and that quicksort's average case is about $2n\log_\mathrm{e}n$.
Proof that quicksort's running time is 1.39 n log n
algorithm analysis;runtime analysis;sorting;quicksort