Add: Reverse Linked List

Author: openset

problems/reverse-linked-list/reverse_linked_list.go

@@ -1 +1,18 @@
 package reverse_linked_list
+
+import . "github.com/openset/leetcode/internal/kit"
+
+/**
+ * Definition for singly-linked list.
+ * type ListNode struct {
+ *     Val int
+ *     Next *ListNode
+ * }
+ */
+func reverseList(head *ListNode) *ListNode {
+	var pre *ListNode
+	for head != nil {
+		pre, head, head.Next = head, head.Next, pre
+	}
+	return pre
+}

problems/reverse-linked-list/reverse_linked_list_test.go

@@ -1 +1,28 @@
 package reverse_linked_list
+
+import (
+	"reflect"
+	"testing"
+
+	. "github.com/openset/leetcode/internal/kit"
+)
+
+type caseType struct {
+	input    []int
+	expected []int
+}
+
+func TestReverseList(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    []int{1, 2, 3, 4, 5},
+			expected: []int{5, 4, 3, 2, 1},
+		},
+	}
+	for _, tc := range tests {
+		output := ListNode2SliceInt(reverseList(SliceInt2ListNode(tc.input)))
+		if !reflect.DeepEqual(output, tc.expected) {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}