# Package heap

## Overview ▹

## Index ▹

## func Fix ¶ 1.2

func Fix(h Interface, i int)

Fix re-establishes the heap ordering after the element at index i has changed its value. Changing the value of the element at index i and then calling Fix is equivalent to, but less expensive than, calling Remove(h, i) followed by a Push of the new value. The complexity is O(log n) where n = h.Len().

## func Init ¶

func Init(h Interface)

Init establishes the heap invariants required by the other routines in this package. Init is idempotent with respect to the heap invariants and may be called whenever the heap invariants may have been invalidated. The complexity is O(n) where n = h.Len().

## func Pop ¶

func Pop(h Interface) interface{}

Pop removes and returns the minimum element (according to Less) from the heap. The complexity is O(log n) where n = h.Len(). Pop is equivalent to Remove(h, 0).

## func Push ¶

func Push(h Interface, x interface{})

Push pushes the element x onto the heap. The complexity is O(log n) where n = h.Len().

## func Remove ¶

func Remove(h Interface, i int) interface{}

Remove removes and returns the element at index i from the heap. The complexity is O(log n) where n = h.Len().

## type Interface ¶

The Interface type describes the requirements for a type using the routines in this package. Any type that implements it may be used as a min-heap with the following invariants (established after Init has been called or if the data is empty or sorted):

!h.Less(j, i) for 0 <= i < h.Len() and 2*i+1 <= j <= 2*i+2 and j < h.Len()

Note that Push and Pop in this interface are for package heap's implementation to call. To add and remove things from the heap, use heap.Push and heap.Pop.

type Interface interface { sort.Interface Push(x interface{}) // add x as element Len() Pop() interface{} // remove and return element Len() - 1. }