Add_Two_Numbers.go

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
 
    // Check that l1 and l2 are not empty
    if l1 == nil && l2 == nil{
        fmt.Printf("2 Empty Nodes Found")
        return nil
    }else if l1 == nil{
        return l2
    }else if l2 == nil{
        return l1
    }
    // assuming that each node can only hold a single digit integer
    // set initial variables to use inside loop
    carryOver := 0
    returnNode:= &ListNode{}
    currentReturnNode:= returnNode
    fn:= l1
    sn:= l2
    fnEnded:= false
    snEnded:= false
    // golang version of while loop
    for{
       
        fv:= fn.Val 
        sv:= sn.Val
        sum:= fv + sv + carryOver
        if sum > 9{
            carryOver = 1
        }else {
            carryOver = 0
        }
        currentReturnNode.Val = sum % 10
        
        if fn.Next == nil{
            fnEnded = true
            fn = &ListNode{}
        }else{
            fn = fn.Next
        }
        if sn.Next == nil{
            snEnded = true
            sn = &ListNode{}
        }else{
            sn = sn.Next
        }
        if fnEnded && snEnded && carryOver == 0{
            return returnNode
        }else{
             currentReturnNode.Next = &ListNode{}
             currentReturnNode = currentReturnNode.Next
        }
        
    }
    
}