002.go

package p002

/**
You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
*/

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
type ListNode struct {
	Val  int
	Next *ListNode
}

func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
	var result = &ListNode{Val: 0, Next: nil}
	temp := result
	inc := 0
	for l1 != nil || l2 != nil || inc != 0 {
		v1, v2 := 0, 0
		if l1 != nil {
			v1 = l1.Val
			l1 = l1.Next
		}
		if l2 != nil {
			v2 = l2.Val
			l2 = l2.Next
		}
		sum := (v1 + v2 + inc) % 10
		inc = (v1 + v2 + inc) / 10
		temp.Next = &ListNode{Val: sum, Next: nil}
		temp = temp.Next
	}
	return result.Next
}