Delete Middle Element of Singly Linked List

Input: 1 -> 2 -> 3 -> 4 -> 5
Output: 1 -> 2 -> 4 -> 5
Note: If there are odd number of element then delete middle

Input: 1 -> 2 -> 3 -> 4
Output: 1 -> 2 -> 4
Note: If there are even number of element then there will be two middle elements. So we will delete second middle.

Implementation

package main

import "fmt"

type Node struct {
    data int
    next *Node
}

func main() {
    head := &Node{data: 1}
    head.next = &Node{data: 2}
    head.next.next = &Node{data: 3}
    head.next.next.next = &Node{data: 4}
    head.next.next.next.next = &Node{data: 5}
    deleteMiddle(head)
    for head != nil {
        fmt.Printf("%d ", head.data)
        head = head.next
    }
    fmt.Println()

}

func deleteMiddle(head *Node) {
    fast := head
    slow := head
    pre := head

    for fast != nil && fast.next != nil {
        pre = slow
        slow = slow.next
        fast = fast.next.next
    }
    pre.next = slow.next
}