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// Example developed by borrowing from "container/heap/example_intheap_test.go"
// Portions Copyright 2012 by the Go authors
//
// This example demonstrates an integer doubbly-ended heap built using the deheap interface.
package deheap_test
import (
"fmt"
"github.com/aalpar/deheap"
)
// An IntHeap is a min-heap of ints.
type IntDeheap []int
func (h IntDeheap) Len() int { return len(h) }
func (h IntDeheap) Less(i, j int) bool { return h[i] < h[j] }
func (h IntDeheap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
func (h *IntDeheap) 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 *IntDeheap) Pop() interface{} {
old := *h
n := len(old)
x := old[n-1]
*h = old[:n-1]
return x
}
// This example inserts several ints into an IntHeap, checks the minimum,
// and removes them in order of priority.
func Example_intHeap() {
h := &IntDeheap{2, 1, 5, 6}
deheap.Init(h)
deheap.Push(h, 3)
fmt.Printf("minimum: %d\n", (*h)[0])
for h.Len() > 3 {
fmt.Printf("%d ", deheap.PopMax(h))
}
for h.Len() > 1 {
fmt.Printf("%d ", deheap.Pop(h))
}
fmt.Printf("middle value: %d\n", (*h)[0])
// Output:
// minimum: 1
// 6 5 1 2 middle value: 3
}
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