Micro-Drill #142 — Quick select kth largest

Divide & Conquer Target: 10s

Quickselect partitions then recurses into one side. O(n) average for kth element.

def qs(l, r, k):
    p = partition(l, r)
    if p == k: return a[p]
    return qs(p+1, r, k) if p &lt; k else qs(l, p-1, k)

Type it from memory. Go.