SiroDiaz /
DataStructures
| @@ 55-84 (lines=30) @@ | ||
| 52 | * @return mixed The data stored in the given index |
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| 53 | * @throws OutOfBoundsException if index is out bounds. |
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| 54 | */ |
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| 55 | public function get($index) { |
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| 56 | if($index < 0 || $index > $this->size - 1) { |
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| 57 | throw new OutOfBoundsException(); |
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| 58 | } |
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| 59 | ||
| 60 | if($index === 0) { |
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| 61 | return $this->head->data; |
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| 62 | } |
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| 63 | ||
| 64 | if($index === $this->size - 1) { |
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| 65 | return $this->tail->data; |
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| 66 | } |
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| 67 | ||
| 68 | $current = &$this->head; |
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| 69 | if($index < (int) ceil($this->size / 2)) { |
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| 70 | $i = 0; |
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| 71 | while($i < $index) { |
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| 72 | $current = &$current->next; |
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| 73 | $i++; |
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| 74 | } |
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| 75 | } else { |
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| 76 | $i = $this->size; |
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| 77 | while($i > $index) { |
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| 78 | $current = &$current->prev; |
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| 79 | $i--; |
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| 80 | } |
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| 81 | } |
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| 82 | ||
| 83 | return $current->data; |
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| 84 | } |
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| 85 | ||
| 86 | /** |
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| 87 | * Gets the node stored in the position especified. |
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| @@ 94-123 (lines=30) @@ | ||
| 91 | * @throws OutOfBoundsException if it is out of limits (< 0 or > size - 1) |
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| 92 | * @return DataStructures\Lists\Nodes\DoublyLinkedListNode|null the node stored in $index. |
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| 93 | */ |
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| 94 | protected function search($index) { |
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| 95 | if($index < 0 || $index > $this->size - 1) { |
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| 96 | throw new OutOfBoundsException(); |
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| 97 | } |
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| 98 | ||
| 99 | if($index === 0) { |
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| 100 | return $this->head; |
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| 101 | } |
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| 102 | ||
| 103 | if($index === $this->size - 1) { |
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| 104 | return $this->tail; |
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| 105 | } |
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| 106 | ||
| 107 | $current = &$this->head; |
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| 108 | if($index < (int) ceil($this->size / 2)) { |
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| 109 | $i = 0; |
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| 110 | while($i < $index) { |
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| 111 | $current = &$current->next; |
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| 112 | $i++; |
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| 113 | } |
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| 114 | } else { |
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| 115 | $i = $this->size; |
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| 116 | while($i > $index) { |
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| 117 | $current = &$current->prev; |
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| 118 | $i--; |
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| 119 | } |
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| 120 | } |
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| 121 | ||
| 122 | return $current; |
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| 123 | } |
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| 124 | ||
| 125 | /** |
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| 126 | * Returns the data in the last node with O(1). |
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