Is there a more generic way to implement 2 kinds of Heap (Max and Min) in Go Lang

Question

Currently, the example on Go lang doc is like this:

type IntHeap []int

func (h IntHeap) Len() int           { return len(h) }
func (h IntHeap) Less(i, j int) bool { return h[i] < h[j] }
func (h IntHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *IntHeap) Push(x interface{}) {
    // Push and Pop use pointer receivers because they modify the slice's length,
    // not just its contents.
    *h = append(*h, x.(int))
}

func (h *IntHeap) Pop() interface{} {
    old := *h
    n := len(old)
    x := old[n-1]
    *h = old[0 : n-1]
    return x
}

I really don't want to repeat myself creating a set of methods for Min Heap and another set of methods for Max Heap. Is there a better way?

Answer 1

You can create a max heap from your min heap using embedding, like this

type MaxHeap struct {
    IntHeap
}

func (h MaxHeap) Less(i, j int) bool { return h.IntHeap[i] > h.IntHeap[j] }

See the playground for a working example.