deleteDuplicates

delete_duplicates.rb

# Definition for singly-linked list.
# class ListNode
#     attr_accessor :val, :next
#     def initialize(val)
#         @val = val
#         @next = nil
#     end
# end

# @param {ListNode} head
# https://leetcode.com/problems/remove-duplicates-from-sorted-list/submissions/
#Runtime: 40 ms, faster than 71.28% of Ruby online submissions for Remove Duplicates from Sorted List.
#Memory Usage: 9.3 MB, less than 100.00% of Ruby online submissions for Remove Duplicates from Sorted List.
# @return {ListNode}
def delete_duplicates(head)
    pnt1, pnt2 = head, head
    while pnt1 do
        pnt2 = pnt1.next
        while pnt2 && pnt1.val == pnt2.val do
            pnt2 = pnt2.next
        end
        pnt1.next = pnt2
        pnt1 = pnt2
    end
    head
end

deleteDuplicates.go

/**
https://leetcode.com/problems/remove-duplicates-from-sorted-list/submissions/
Runtime: 4 ms, faster than 90.10% of Go online submissions for Remove Duplicates from Sorted List.
Memory Usage: 3.1 MB, less than 50.00% of Go online submissions for Remove Duplicates from Sorted List.
 */
func deleteDuplicates(head *ListNode) *ListNode {
    var pointer, pointer2 * ListNode
    pointer = head
    for ; pointer != nil ; {
        pointer2 = pointer.Next
        for ; pointer2 != nil && pointer2.Val == pointer.Val ; {
            pointer2 = pointer2.Next
        }
        pointer.Next = pointer2
        pointer = pointer2
    }
    return head
    
}

deleteDuplicates.js

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 Runtime: 64 ms, faster than 79.29% of JavaScript online submissions for Remove Duplicates from Sorted List.
Memory Usage: 35.7 MB, less than 43.75% of JavaScript online submissions for Remove Duplicates from Sorted List.
 https://leetcode.com/problems/remove-duplicates-from-sorted-list/submissions/
 */
var deleteDuplicates = function(head) {
    let [pointer,pointer2] = [head,head]
    for( ; pointer != null ;){
        for( pointer2 = pointer.next ; pointer2 != null && pointer2.val == pointer.val; ){
            pointer2 = pointer2.next
        }
        pointer.next = pointer2
        pointer = pointer2
        
    }
    return head
};

deleteDuplicates.py

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
# Runtime: 48 ms, faster than 69.45% of Python3 online submissions for Remove Duplicates from Sorted List.
# Memory Usage: 13.7 MB, less than 6.45% of Python3 online submissions for Remove Duplicates from Sorted List.
# https://leetcode.com/problems/remove-duplicates-from-sorted-list/submissions/
class Solution:
    def deleteDuplicates(self, head: ListNode) -> ListNode:
        pnt1, pnt2 = head, head
        while pnt1:
            pnt2 = pnt1.next
            while pnt2 and pnt1.val == pnt2.val:
                pnt2 = pnt2.next
            pnt1.next = pnt2
            pnt1 = pnt2
        return head
    

https://tour.golang.org/moretypes/4

https://www.iteanz.com/tutorials/python/multiple-assignment/

https://www.pythoncentral.io/python-null-equivalent-none/

https://www.w3schools.com/python/python_while_loops.asp