203. 移除链表元素

203. 移除链表元素

需要设置一个前置节点 这个时候可以需要设置一个哨兵节点dummyHead 可以在删除的第一个节点的时候非常方便处理

package main
import "fmt"
type ListNode struct {
    Val  int
    Next *ListNode
}
func removeElements(head *ListNode, val int) *ListNode {
    dummyHead := &ListNode{
        Val:  -1,
        Next: head,
    }
    preNode := dummyHead
    for head != nil {
        if head.Val == val {
            next := head.Next
            preNode.Next = next
            head = next
        } else {
            preNode = head
            head = head.Next
        }
    }
    return dummyHead.Next
}
func main() {
    one := &ListNode{Val: 1}
    two := ListNode{Val: 2}
    one.Next = &two
    three := ListNode{Val: 6}
    two.Next = &three
    four := ListNode{Val: 3}
    three.Next = &four
    five := ListNode{Val: 4}
    four.Next = &five
    six := ListNode{Val: 5}
    five.Next = &six
    seven := ListNode{Val: 6}
    six.Next = &seven
    removeElements(one, 6)
    curr := one
    for curr != nil {
        fmt.Println(curr.Val)
        curr = curr.Next
    }
}