141. 环形链表 #
题目地址 #
解题思路 #
具体实现 #
```go
package main
import "fmt"
type ListNode struct {
Val int
Next *ListNode
}
func hasCycle(head *ListNode) bool {
slow, fast := head, head
for fast != nil && fast.Next != nil {
slow = slow.Next
fast = fast.Next.Next
if slow == fast {
return true
}
}
return false
}
func main() {
createLinkedList := func(arr []int) *ListNode {
if len(arr) == 0 {
return nil
}
head := &ListNode{Val: arr[0]}
current := head
for i := 1; i < len(arr); i++ {
node := &ListNode{Val: arr[i]}
current.Next = node
current = node
}
// Make it a circular linked list (connect the last node to the head)
current.Next = head
return head
}
arr := []int{1, 2, 3, 4, 5}
head := createLinkedList(arr)
head.Next.Next.Next.Next.Next = head.Next
// Test the hasCycle function
if hasCycle(head) {
fmt.Println("The linked list has a cycle.")
} else {
fmt.Println("The linked list does not have a cycle.")
}
}
```