61 runtime error

Author: aQua

Algorithms/0061.rotate-list/rotate-list.go

@@ -1,9 +1,5 @@
 package Problem0061
 
-import (
-	"fmt"
-)
-
 // ListNode 是题目预定义的节点
 type ListNode struct {
 	Val  int
@@ -12,22 +8,23 @@ type ListNode struct {
 
 func rotateRight(head *ListNode, k int) *ListNode {
 	end := head
-	cnt := 1
+	// size 是 List 的长度
+	size := 1
 	for end.Next != nil {
 		end = end.Next
-		cnt++
+		size++
 	}
-	fmt.Println(cnt)
 
 	end.Next = head
-	fmt.Println(l2s(end))
 
-	cnt -= k % cnt
+	// steps 是 head 需要移动的步数
+	// k%size 因为 k 很可能大于 size
+	steps := size - k%size
 
-	for cnt > 1 {
+	for steps > 0 {
 		head = head.Next
 		end = end.Next
-		cnt--
+		steps--
 	}
 
 	end.Next = nil

Algorithms/0061.rotate-list/rotate-list_test.go

@@ -28,6 +28,16 @@ func Test_Problem0061(t *testing.T) {
 
 	qs := []question{
 
+		question{
+			para{
+				[]int{},
+				0,
+			},
+			ans{
+				[]int{},
+			},
+		},
+
 		question{
 			para{
 				[]int{1, 2, 3, 4, 5},