Week 02b: Analysis of Algorithms (36)

Example: Computing Prefix Averages (cont)

The following algorithm computes prefix averages by keeping a running sum:

prefixAverages2(X):
|  Input  array X of n integers
|  Output array A of prefix averages of X
|
|  s=0
|  for all i=0..n-1 do          O(n)
|     s=s+X[i]                  O(n)
|     A[i]=s/(i+1)              O(n)
|  end for
|  return A                     O(1)

Thus, prefixAverages2 is O(n)