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top-100-liked/23/23_test.go

@@ -0,0 +1,55 @@
+package top100liked
+
+import (
+	"fmt"
+	"testing"
+)
+
+// https://leetcode.cn/problems/reverse-linked-list/description/?envType=study-plan-v2&envId=top-100-liked
+
+type ListNode struct {
+	Val  int
+	Next *ListNode
+}
+
+func reverseList(head *ListNode) *ListNode {
+	if head == nil {
+		return nil
+	}
+	var last *ListNode = nil
+	h := head
+	for h.Next != nil {
+		tmp := h.Next
+		h.Next = last
+		last = h
+		h = tmp
+	}
+	h.Next = last
+	return h
+}
+
+func TestS23(t *testing.T) {
+	input := ListNode{
+		Val: 1,
+		Next: &ListNode{
+			Val: 2,
+			Next: &ListNode{
+				Val: 3,
+				Next: &ListNode{
+					Val: 4,
+					Next: &ListNode{
+						Val:  5,
+						Next: nil,
+					},
+				},
+			},
+		},
+	}
+	output := reverseList(&input)
+
+	for output.Next != nil {
+		fmt.Println(output.Val)
+		output = output.Next
+	}
+	fmt.Println(output.Val)
+}