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27 lines
973 B
HTML
27 lines
973 B
HTML
<p>Given the <code>root</code> of a binary tree, <em>check whether it is a mirror of itself</em> (i.e., symmetric around its center).</p>
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<p> </p>
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<p><strong class="example">Example 1:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2021/02/19/symtree1.jpg" style="width: 354px; height: 291px;" />
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<pre>
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<strong>Input:</strong> root = [1,2,2,3,4,4,3]
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<strong>Output:</strong> true
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</pre>
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<p><strong class="example">Example 2:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2021/02/19/symtree2.jpg" style="width: 308px; height: 258px;" />
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<pre>
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<strong>Input:</strong> root = [1,2,2,null,3,null,3]
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<strong>Output:</strong> false
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li>The number of nodes in the tree is in the range <code>[1, 1000]</code>.</li>
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<li><code>-100 <= Node.val <= 100</code></li>
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</ul>
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<p> </p>
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<strong>Follow up:</strong> Could you solve it both recursively and iteratively? |