CS 361

Heaps

Pseudo code for adding/removing from a heap:

push(v){
    // Ensure the array A is big enough
    // Add v to last slot in array A

    curr = A.length - 1
    p = parent(curr)
    while(A[curr] and A[p] violate max heap property){
         // Swap values A[curr] and A[p]
         // Update curr and p
    }
}

pop(){
    // Swap the values A[0] and A[A.length-1]

    curr = 0
    left = getLeft(curr)
    right = getRight(curr)
    while(max heap property is violated by curr, left, right){
         // Determine which child has larger value
         // Swap curr with this child
         // Update curr, left, right
    }
    // Remove A[A.length-1] from array
    // Return this element back
}