imajinyun /
leetcode-php
| Conditions | 5 |
| Paths | 6 |
| Total Lines | 20 |
| Code Lines | 13 |
| Lines | 0 |
| Ratio | 0 % |
| Changes | 1 | ||
| Bugs | 0 | Features | 0 |
| 1 | <?php |
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| 26 | public static function invertTree2(?TreeNode $root): ?TreeNode |
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| 27 | { |
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| 28 | if (!$root) { |
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| 29 | return null; |
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| 30 | } |
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| 31 | $stack = [$root]; |
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| 32 | while ($stack) { |
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| 33 | $node = array_pop($stack); |
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| 34 | $left = $node->left; |
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| 35 | $node->left = $node->right; |
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| 36 | $node->right = $left; |
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| 37 | if ($node->left) { |
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| 38 | array_push($stack, $node->left); |
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| 39 | } |
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| 40 | if ($node->right) { |
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| 41 | array_push($stack, $node->right); |
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| 42 | } |
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| 43 | } |
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| 44 | |||
| 45 | return $root; |
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| 46 | } |
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| 48 |
This check marks implicit conversions of arrays to boolean values in a comparison. While in PHP an empty array is considered to be equal (but not identical) to false, this is not always apparent.
Consider making the comparison explicit by using
empty(..)or! empty(...)instead.