Constructing a Binary Heap

A binary heap can  be constructed in O ( n ) time

1. Create an array and store the n elements in arbitrary order
   
   
   
2. "Heapify" the array
   
   start at vertex i = |_ n / 2_|, the left most vertex in the the
   next to last level
   for each vertex from i up to the root, shift down
   
   
   

Example

    Construct a binary heap from the values {18, 2, 13, 10, 15, 3, 7, 16, 8}