package main

import (
    "fmt"
)

type ListNode struct {
    Next  *ListNode
    Value int
}

func RemoveNodeNormal(head *ListNode, value int) *ListNode {
    var prev *ListNode
    for cur := head; cur != nil; cur = cur.Next {
        if cur.Value == value {
            if prev != nil {
                prev.Next = cur.Next
            } else {
                head = cur.Next
            }
        } else {
            prev = cur
        }
    }
    return head
}

func RemoveNodeReplace(head *ListNode, value int) *ListNode {
    cur := head
    for cur != nil && cur.Value == value {
        if cur.Next == nil {
            return nil
        }
        cur.Value = cur.Next.Value
        cur.Next = cur.Next.Next
    }
    for cur != nil {
        if cur.Next != nil && cur.Next.Value == value {
            cur.Next = cur.Next.Next
        } else {
            cur = cur.Next
        }
    }
    return head
}

func RemoveNode(head *ListNode, value int) *ListNode {
    for cur := &head; *cur != nil; {
        if (*cur).Value == value {
            *cur = (*cur).Next
        } else {
            cur = &(*cur).Next
        }
    }
    return head
}

func ArrayToLink(nums []int) *ListNode {
    if len(nums) == 0 {
        return nil
    }
    head := &ListNode{
        Value: nums[0],
    }
    tail := head
    for i := 1; i < len(nums); i++ {
        tail.Next = &ListNode{
            Value: nums[i],
        }
        tail = tail.Next
    }
    return head
}

func LinkToArray(head *ListNode) []int {
    var array []int
    for ; head != nil; head = head.Next {
        array = append(array, head.Value)
    }
    return array
}

func ArrayEqual(nums1, nums2 []int) bool {
    if len(nums1) != len(nums2) {
        return false
    }
    for i := 0; i < len(nums1); i++ {
        if nums1[i] != nums2[i] {
            return false
        }
    }
    return true
}

func main() {
    tests := []struct {
        nums  []int
        value int
        res   []int
    }{
        {
            []int{},
            1,
            []int{},
        },
        {
            []int{1},
            1,
            []int{},
        },
        {
            []int{1, 2},
            1,
            []int{2},
        },
        {
            []int{1, 2},
            2,
            []int{1},
        },
        {
            []int{1, 2, 1, 3, 1, 4, 1, 1, 1, 1, 1},
            1,
            []int{2, 3, 4},
        },
        {
            []int{1, 2, 3, 2, 4, 2},
            2,
            []int{1, 3, 4},
        },
        {
            []int{3, 1, 3, 2, 3, 4, 3},
            3,
            []int{1, 2, 4},
        },
        {
            []int{4, 1, 4, 2, 4, 3, 4, 4, 4, 4, 4},
            4,
            []int{1, 2, 3},
        },
    }

    for _, test := range tests {
        head := ArrayToLink(test.nums)
        head = RemoveNode(head, test.value)
        array := LinkToArray(head)
        fmt.Println(ArrayEqual(array, test.res))
    }
}