search

theodesp / go-heaps

Reference implementations of heap data structures in Go - treap, skew, leftlist, pairing, fibonacci
MIT License
97 stars 29 forks source link

feat(leftist heap): change test to fit example and then fix the test #38

Closed lhauspie closed 6 years ago

lhauspie commented 6 years ago

$ go run example/leftist/leftist.go was raising:

panic: interface conversion: go_heaps.Item is nil, not go_heaps.Integer

goroutine 1 [running]:
github.com/theodesp/go-heaps.Integer.Compare(...)
        /home/lhauspie/go/src/github.com/theodesp/go-heaps/heap.go:77
github.com/theodesp/go-heaps.(*Integer).Compare(0xc42001c100, 0x0, 0x0, 0xc42007c180)
        <autogenerated>:1 +0x9d
github.com/theodesp/go-heaps/leftist.mergeNodes(0xc42007c180, 0xc42007c150, 0x7f299e107200)
        /home/lhauspie/go/src/github.com/theodesp/go-heaps/leftist/leftist_heap.go:28 +0x5f
github.com/theodesp/go-heaps/leftist.(*LeftistHeap).Insert(0xc420049f28, 0x51c220, 0xc42001c100, 0xc42001c100, 0xc42008a168)
        /home/lhauspie/go/src/github.com/theodesp/go-heaps/leftist/leftist_heap.go:67 +0x6b
main.main()
        /home/lhauspie/go/src/github.com/theodesp/go-heaps/example/leftist/leftist.go:12 +0xa0
exit status 2

because the Init function of leftist heap was:

func (h *LeftistHeap) Init() *LeftistHeap {
    h.root = &Node{} // <==== Item is nil here
    return h
}

So when we first tried to insert an Item, the mergeNodes function was comparing the item of the new node with the item of the heap root wich was nil and then failed