package q1046

import "container/heap"

type IntHeap []int

func (h *IntHeap) Len() int               { return len(*h) }
func (h *IntHeap) Less(i int, j int) bool { return (*h)[i] > (*h)[j] }
func (h *IntHeap) Push(x any)             { *h = append(*h, x.(int)) }
func (h *IntHeap) Swap(i int, j int)      { (*h)[i], (*h)[j] = (*h)[j], (*h)[i] }

func (h *IntHeap) Pop() any {
	ret := (*h)[len(*h)-1]
	*h = (*h)[:len(*h)-1]
	return ret
}

func lastStoneWeight(stones []int) int {
	var st IntHeap = stones
	heap.Init(&st)

	for st.Len() > 1 {
		a, b := heap.Pop(&st).(int), heap.Pop(&st).(int)
		rem := a - b
		if rem < 0 {
			rem = -rem
		}
		if rem > 0 {
			heap.Push(&st, rem)
		}
	}

	if st.Len() > 0 {
		return st[0]
	}
	return 0
}

var _ = lastStoneWeight