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Doubly-linked list/Element insertion: Difference between revisions
Doubly-linked list/Element insertion (view source)
Revision as of 14:57, 4 October 2021
, 2 years agoAdd swift
(Add swift) |
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Line 1,316:
}
}</lang>
=={{header|Swift}}==
<lang swift>typealias NodePtr<T> = UnsafeMutablePointer<Node<T>>
class Node<T> {
var value: T
fileprivate var prev: NodePtr<T>?
fileprivate var next: NodePtr<T>?
init(value: T, prev: NodePtr<T>? = nil, next: NodePtr<T>? = nil) {
self.value = value
self.prev = prev
self.next = next
}
}
@discardableResult
func insert<T>(_ val: T, after: Node<T>? = nil, list: NodePtr<T>? = nil) -> NodePtr<T> {
let node = NodePtr<T>.allocate(capacity: 1)
node.initialize(to: Node(value: val))
var n = list
while n != nil {
if n?.pointee !== after {
n = n?.pointee.next
continue
}
node.pointee.prev = n
node.pointee.next = n?.pointee.next
n?.pointee.next?.pointee.prev = node
n?.pointee.next = node
break
}
return node
}
// [1]
let list = insert(1)
// [1, 2]
insert(2, after: list.pointee, list: list)
// [1, 3, 2]
insert(3, after: list.pointee, list: list)</lang>
=={{header|Tcl}}==
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