go string heap example

heap.go

package main

import (
	"fmt"
	"container/heap"
)

type StringHeap []string

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

func (h *StringHeap) Push(x interface{}) {
	*h = append(*h, x.(string))
}

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

func main() {
	h := &StringHeap{"a", "ccc", "bb"}
	heap.Init(h)
	heap.Push(h, "dddd")
	fmt.Printf("minimum: %s\n", (*h)[0])
	for h.Len() > 0 {
		fmt.Printf("%s\n", heap.Pop(h))
	}
}