Chunksort: A Generalized Partial Sorting Algorithm

We introduce here the problem of generalized partial sorting and chunksort, an algorithm closely related to quicksort and quickselect that solves this problem in an elegant and efficient way. In generalized partial sorting we are given an array of n elements and p intervals I1 = [`1,u1], I2 = [`2,u2], . . . , Ip = [`p,up], which define p blocks in the array and p+1 gaps between the blocks. The goal is to sort the blocks and gaps relative to each other, and furthermore sort the elements within each block. We provide an analysis of the average performance of chunksort and show how it generalizes well known results for quicksort, quickselect, multiple quickselect and partial quicksort.