Add Add :) Two Numbers solution

Author: lon-io

add_two_numbers.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+    "fmt"
+    "strconv"
+    "strings"
+)
+
+type ListNode struct {
+	Val int
+	Next *ListNode
+}
+
+func walk (l *ListNode, a *string) {
+    v := l.Val
+    *a =  *a + fmt.Sprintf("%d", v)
+
+    if l.Next != nil {
+        walk(l.Next, a)
+    }
+}
+
+func extendLinkedList(ln *ListNode, acc []string, ci int) {
+    cmp := len(acc) - ci - 1
+    iSum, _ := strconv.ParseInt(acc[cmp], 10, 32)
+    ln.Val = int(iSum)
+
+    if cmp != 0 {
+        next := ListNode{}
+        ln.Next = &next
+        extendLinkedList(ln.Next, acc, ci + 1)
+    }
+}
+
+func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
+    acc1 := ""
+    acc2 := ""
+
+    walk(l1, &acc1)
+    walk(l2, &acc2)
+
+    lng := acc1
+    srt := acc2
+    if len(acc1) < len(acc2) {
+        lng = acc2
+        srt = acc1
+    }
+
+    sumStr := ""
+    carry := 0
+    for i := 0; i <= len(lng); i ++ {
+        if i == len(lng) {
+            if carry > 0 {
+                sumStr = fmt.Sprintf("%d", carry) + sumStr
+            }
+        } else {
+            var vs, vl string
+
+            if i < len(srt)  {
+                vs = string(srt[i])
+            }
+
+            vl = string(lng[i])
+            ds, _ := strconv.Atoi(vs)
+            dl, _ := strconv.Atoi(vl)
+
+            sI := ds + dl + carry
+            carry = sI / 10
+            sI = sI % 10
+
+            fmt.Printf("\n Index: %d ::: short %d + long %d ==> %d;; carry: %d", i, ds, dl, sI, carry)
+            sumStr = fmt.Sprintf("%d", sI) + sumStr
+        }
+    }
+
+    fmt.Printf("\n FINAL SUM::: %s", sumStr)
+    sumSl := strings.Split(sumStr, "")
+
+    lnSum := ListNode{}
+    extendLinkedList(&lnSum, sumSl, 0)
+
+    return &lnSum
+}
+
+func extendTestCaseLinkedList(ln *ListNode, acc []int, ci int) {
+    iSum := acc[ci]
+    ln.Val = int(iSum)
+
+    if ci < len(acc) - 1 {
+        next := ListNode{}
+        ln.Next = &next
+        extendTestCaseLinkedList(ln.Next, acc, ci + 1)
+    }
+}
+
+func main() {
+	// Generated Test Case
+	test1 := []int{1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}
+	test2 := []int{5,6,4}
+
+	var listNode1, listNode2 ListNode
+	extendTestCaseLinkedList(&listNode1, test1, 0)
+	extendTestCaseLinkedList(&listNode2, test2, 0)
+
+	addTwoNumbers(&listNode1, &listNode2)
+}