1046-last-stone-weight.go

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{}) {*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
}

type KthLargest struct {
    minHeap *IntHeap
    k int
}

func lastStoneWeight(_stones []int) int {
    for s := 0; s < len(_stones); s++ {
        _stones[s] *= -1
    }
    stones := IntHeap(_stones)
    heap.Init(&stones)
    
    for len(stones) > 1 {
        first, _ := heap.Pop(&stones).(int)
        second, _ := heap.Pop(&stones).(int)
        if second > first {
            heap.Push(&stones, first - second)
        }
    }
    stones = append(stones, 0)
    return abs(stones[0])
}

func abs(x int) int {
    if x < 0 {
        return -x
    }
    return x
}