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| 1 | +#Lista Enlazada (Linked List) |
| 2 | + |
| 3 | +_Lee esto en otros idiomas:_ |
| 4 | +[_简体中文_](README.zh-CN.md), |
| 5 | +[_Русский_](README.ru-RU.md), |
| 6 | +[_日本語_](README.ja-JP.md), |
| 7 | +[_Português_](README.pt-BR.md) |
| 8 | +[_English_](README.md) |
| 9 | + |
| 10 | +En ciencias de la computaciòn una**lista enlazada** es una coleccion linear |
| 11 | +de elemntos de datos, en los cuales el orden linear no es dado por |
| 12 | +su posciòn fisica en memoria. En cambio, cada |
| 13 | +elemento señala al siguiente. Es una estructura de datos |
| 14 | +que consiste en un grupo de nodos los cuales juntos representan |
| 15 | +una secuencia. Bajo la forma mas simple, cada nodo es |
| 16 | +compuesto de datos y una referencia (en otras palabras, |
| 17 | +un lazo) al siguiente nodo en la secuencia. Esta estructura |
| 18 | +permite la insercion o remocion de elementos |
| 19 | +desde cualquier posicion en la secuencia durante la iteracion. |
| 20 | +Variantes mas complejas agregan lazos adicionales, permitiendo |
| 21 | +una eficiente insercion o remocion desde referencias arbitrarias |
| 22 | +del elemento. Una desventaja de las listas lazadas es que el tiempo de |
| 23 | +acceso es linear (y dificil de canalizar) Un acceso |
| 24 | +mas rapido, como un acceso aleatorio, no es factible. Los arreglos |
| 25 | +tienen una mejor locazion comparados con las listas lazadas. |
| 26 | + |
| 27 | + |
| 28 | + |
| 29 | + |
| 30 | +##Pseudocodigo para operacones basicas |
| 31 | + |
| 32 | +###Insertar |
| 33 | + |
| 34 | +```text |
| 35 | +Add(value) |
| 36 | + Pre: value is the value to add to the list |
| 37 | + Post: value has been placed at the tail of the list |
| 38 | + n ← node(value) |
| 39 | + if head = ø |
| 40 | + head ← n |
| 41 | + tail ← n |
| 42 | + else |
| 43 | + tail.next ← n |
| 44 | + tail ← n |
| 45 | + end if |
| 46 | +end Add |
| 47 | +``` |
| 48 | + |
| 49 | +```text |
| 50 | +Prepend(value) |
| 51 | + Pre: value is the value to add to the list |
| 52 | + Post: value has been placed at the head of the list |
| 53 | + n ← node(value) |
| 54 | + n.next ← head |
| 55 | + head ← n |
| 56 | + if tail = ø |
| 57 | + tail ← n |
| 58 | + end |
| 59 | +end Prepend |
| 60 | +``` |
| 61 | + |
| 62 | +###Buscar |
| 63 | + |
| 64 | +```text |
| 65 | +Contains(head, value) |
| 66 | + Pre: head is the head node in the list |
| 67 | + value is the value to search for |
| 68 | + Post: the item is either in the linked list, true; otherwise false |
| 69 | + n ← head |
| 70 | + while n != ø and n.value != value |
| 71 | + n ← n.next |
| 72 | + end while |
| 73 | + if n = ø |
| 74 | + return false |
| 75 | + end if |
| 76 | + return true |
| 77 | +end Contains |
| 78 | +``` |
| 79 | + |
| 80 | +###Borrar |
| 81 | + |
| 82 | +```text |
| 83 | +Remove(head, value) |
| 84 | + Pre: head is the head node in the list |
| 85 | + value is the value to remove from the list |
| 86 | + Post: value is removed from the list, true, otherwise false |
| 87 | + if head = ø |
| 88 | + return false |
| 89 | + end if |
| 90 | + n ← head |
| 91 | + if n.value = value |
| 92 | + if head = tail |
| 93 | + head ← ø |
| 94 | + tail ← ø |
| 95 | + else |
| 96 | + head ← head.next |
| 97 | + end if |
| 98 | + return true |
| 99 | + end if |
| 100 | + while n.next != ø and n.next.value != value |
| 101 | + n ← n.next |
| 102 | + end while |
| 103 | + if n.next != ø |
| 104 | + if n.next = tail |
| 105 | + tail ← n |
| 106 | + end if |
| 107 | + n.next ← n.next.next |
| 108 | + return true |
| 109 | + end if |
| 110 | + return false |
| 111 | +end Remove |
| 112 | +``` |
| 113 | + |
| 114 | +###Atrevesar |
| 115 | + |
| 116 | +```text |
| 117 | +Traverse(head) |
| 118 | + Pre: head is the head node in the list |
| 119 | + Post: the items in the list have been traversed |
| 120 | + n ← head |
| 121 | + while n != ø |
| 122 | + yield n.value |
| 123 | + n ← n.next |
| 124 | + end while |
| 125 | +end Traverse |
| 126 | +``` |
| 127 | + |
| 128 | +###Atravesar en Reversa |
| 129 | + |
| 130 | +```text |
| 131 | +ReverseTraversal(head, tail) |
| 132 | + Pre: head and tail belong to the same list |
| 133 | + Post: the items in the list have been traversed in reverse order |
| 134 | + if tail != ø |
| 135 | + curr ← tail |
| 136 | + while curr != head |
| 137 | + prev ← head |
| 138 | + while prev.next != curr |
| 139 | + prev ← prev.next |
| 140 | + end while |
| 141 | + yield curr.value |
| 142 | + curr ← prev |
| 143 | + end while |
| 144 | + yield curr.value |
| 145 | + end if |
| 146 | +end ReverseTraversal |
| 147 | +``` |
| 148 | + |
| 149 | +##Complexities |
| 150 | + |
| 151 | +###Time Complexity |
| 152 | + |
| 153 | +| Access| Search| Insertion| Deletion| |
| 154 | +| :-------:| :-------:| :-------:| :-------:| |
| 155 | +| O(n)| O(n)| O(1)| O(n)| |
| 156 | + |
| 157 | +###Space Complexity |
| 158 | + |
| 159 | +O(n) |
| 160 | + |
| 161 | +##References |
| 162 | + |
| 163 | +-[Wikipedia](https://en.wikipedia.org/wiki/Linked_list) |
| 164 | +-[YouTube](https://www.youtube.com/watch?v=njTh_OwMljA&index=2&t=1s&list=PLLXdhg_r2hKA7DPDsunoDZ-Z769jWn4R8) |