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47 lines
1.8 KiB
HTML
47 lines
1.8 KiB
HTML
<p>You are given a nested list of integers <code>nestedList</code>. Each element is either an integer or a list whose elements may also be integers or other lists. Implement an iterator to flatten it.</p>
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<p>Implement the <code>NestedIterator</code> class:</p>
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<ul>
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<li><code>NestedIterator(List<NestedInteger> nestedList)</code> Initializes the iterator with the nested list <code>nestedList</code>.</li>
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<li><code>int next()</code> Returns the next integer in the nested list.</li>
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<li><code>boolean hasNext()</code> Returns <code>true</code> if there are still some integers in the nested list and <code>false</code> otherwise.</li>
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</ul>
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<p>Your code will be tested with the following pseudocode:</p>
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<pre>
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initialize iterator with nestedList
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res = []
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while iterator.hasNext()
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append iterator.next() to the end of res
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return res
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</pre>
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<p>If <code>res</code> matches the expected flattened list, then your code will be judged as correct.</p>
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<p> </p>
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<p><strong class="example">Example 1:</strong></p>
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<pre>
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<strong>Input:</strong> nestedList = [[1,1],2,[1,1]]
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<strong>Output:</strong> [1,1,2,1,1]
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<strong>Explanation:</strong> By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1,1,2,1,1].
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</pre>
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<p><strong class="example">Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> nestedList = [1,[4,[6]]]
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<strong>Output:</strong> [1,4,6]
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<strong>Explanation:</strong> By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1,4,6].
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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><code>1 <= nestedList.length <= 500</code></li>
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<li>The values of the integers in the nested list is in the range <code>[-10<sup>6</sup>, 10<sup>6</sup>]</code>.</li>
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</ul>
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