func mergeTwoLists(a, b *ListNode) *ListNode {

about this snippet

This is the mergelists snippet in Go — a classic LeetCode interview problem. Type it through to build the muscle memory you need to write it under interview pressure. DeveloperType scores you on net WPM and accuracy and only counts runs above 95% accuracy on the leaderboard, so practice rewards precision, not speed alone.

func mergeTwoLists(a, b *ListNode) *ListNode {
	dummy := &ListNode{}
	tail := dummy
	for a != nil && b != nil {
		if a.Val <= b.Val {
			tail.Next = a
			a = a.Next
		} else {
			tail.Next = b
			b = b.Next
		}
		tail = tail.Next
	}
	if a != nil {
		tail.Next = a
	} else {
		tail.Next = b
	}
	return dummy.Next
}