Page Comparison

func kSmallestPairs(nums1 []int, nums2 []int, k int) [][]int {
    result := make([][]int, 0, k)
    
    h_ := make(Heap, 0, k)
    h := &h_
    
    for _, num := range nums1 {
        heap.Push(h, []int{num, nums2[0], 0})
    }
    
    for i := 0; i < k; i++ {
        top := heap.Pop(h).([]int)
        result = append(result, []int{top[0], top[1]})
        
        if p := top[2] + 1; p < len(nums2) {
            heap.Push(h, []int{top[0], nums2[p], p})
        }
    }
    
    return result
}

type Heap [][]int

func (h Heap) Len() int           { return len(h) }
func (h Heap) Less(i, j int) bool { return h[i][0] + h[i][1] < h[j][0] + h[j][1] }
func (h Heap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }
func (h *Heap) Push(x any) {
	*h = append(*h, x.([]int))
}

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

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
    dummy := &ListNode{}
    
    h := dummy
    h1, h2 := l1, l2
    
    carry := 0
    for h1 != nil || h2 != nil {
        num1, num2 := 0, 0
        
        if h1 != nil && h2 != nil {
            num1, num2 = h1.Val, h2.Val
            h1 = h1.Next
            h2 = h2.Next
        } else if h1 != nil {
            num1 = h1.Val
            h1 = h1.Next
        } else {
            num2 = h2.Val
            h2 = h2.Next
        }
        
        result := num1 + num2 + carry
        if result >= 10 {
            result -= 10
            carry = 1
        } else {
            carry = 0
        }

        node := &ListNode{Val: result}
        h.Next = node
        h = node
    }
    
    if carry > 0 {
        node := &ListNode{Val: carry}
        h.Next = node
        h = node
    }
    
    return dummy.Next
}