add: 220216 [golang]

2202/220216.go

@@ -0,0 +1,63 @@
+package main
+
+import "fmt"
+
+/**
+ * Definition for singly-linked list.
+ */
+
+type ListNode struct {
+	Val  int
+	Next *ListNode
+}
+
+func swapPairs(head *ListNode) *ListNode {
+	ret := ListNode{0, head}
+	ptr := &ret
+
+	for ptr != nil {
+		ptrN := ptr.Next
+		if ptrN == nil {
+			break
+		}
+
+		ptrNN := ptrN.Next
+		if ptrNN == nil {
+			break
+		}
+
+		ptrNNN := ptrNN.Next
+
+		ptr, ptrNN.Next, ptr.Next, ptrN.Next = ptrN, ptrN, ptrNN, ptrNNN
+	}
+
+	return ret.Next
+}
+
+func main() {
+	head := &ListNode{
+		Val: 1,
+		Next: &ListNode{
+			Val: 2,
+			Next: &ListNode{
+				Val: 3,
+				Next: &ListNode{
+					Val: 4,
+					Next: &ListNode{
+						Val: 5,
+						Next: &ListNode{
+							Val:  6,
+							Next: nil,
+						},
+					},
+				},
+			},
+		},
+	}
+
+	head = swapPairs(head)
+
+	for ptr := head; ptr != nil; ptr = ptr.Next {
+		fmt.Println(ptr.Val)
+	}
+}