finish Problem 24

添加了一个简介明了的解答

Author: aQua

Algorithms/0024.swap-nodes-in-pairs/swap-nodes-in-pairs.go

@@ -11,25 +11,9 @@ func swapPairs(head *ListNode) *ListNode {
 		return head
 	}
 
-	var cur *ListNode
-	head = swap(head)
-	cur = head.Next
+	t := head.Next
+	head.Next = swapPairs(t.Next)
+	t.Next = head
 
-	for cur != nil && cur.Next != nil {
-		cur.Next = swap(cur.Next)
-		cur = cur.Next.Next
-	}
-
-	return head
-}
-
-func swap(l *ListNode) *ListNode {
-	if l.Next != nil {
-		temp := l.Next
-		l.Next = temp.Next
-		temp.Next = l
-		return temp
-	}
-
-	return l
+	return t
 }

Algorithms/0024.swap-nodes-in-pairs/swap-nodes-in-pairs_test.go

@@ -60,10 +60,6 @@ func Test_Problem0024(t *testing.T) {
 	}
 }
 
-func Test_swap(t *testing.T) {
-	assert.Equal(t, []int{2, 1, 3, 4}, l2s(swap(s2l([]int{1, 2, 3, 4}))), "swap没能成功转换")
-}
-
 // convert *ListNode to []int
 func l2s(head *ListNode) []int {
 	res := []int{}