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<?php |
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declare(strict_types=1); |
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namespace leetcode; |
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class FindMedianFromDataStream |
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{ |
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private \SplMinHeap $small; |
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private \SplMaxHeap $large; |
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private bool $isEven = true; |
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private \SplMinHeap $min; |
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private \SplMinHeap $max; |
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public function __construct() |
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{ |
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$this->small = new \SplMinHeap(); |
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$this->large = new \SplMaxHeap(); |
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$this->min = new \SplMinHeap(); |
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$this->max = new \SplMinHeap(); |
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} |
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public function addNum(int $num): void |
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{ |
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if ($this->isEven) { |
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$this->large->insert($num); |
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$this->small->insert($this->large->extract()); |
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} else { |
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$this->small->insert($num); |
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$this->large->insert($this->small->extract()); |
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} |
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$this->isEven = !$this->isEven; |
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} |
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public function addNum2(int $num): void |
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{ |
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$this->max->insert($num); |
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$this->min->insert(-$this->max->extract()); |
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if ($this->min->count() > $this->max->count()) { |
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$this->max->insert(-$this->min->extract()); |
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} |
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} |
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public function findMedian(): float |
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{ |
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if ($this->isEven) { |
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return !$this->small->isEmpty() && !$this->large->isEmpty() |
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? ($this->small->top() + $this->large->top()) / 2.0 |
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: 0; |
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} else { |
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return $this->small->isEmpty() ? 0 : $this->small->top(); |
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} |
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} |
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public function findMedian2(): float |
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{ |
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if ($this->min->count() < $this->max->count()) { |
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return $this->max->isEmpty() ? 0 : $this->max->top(); |
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} else { |
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$max = $this->max->isEmpty() ? 0 : $this->max->top(); |
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$min = $this->min->isEmpty() ? 0 : $this->min->top(); |
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return ($max - $min) / 2.0; |
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} |
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} |
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} |
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