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			37 lines
		
	
	
		
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			37 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
<p>Given an array of positive integers <code>arr</code> (not necessarily distinct), return <em>the </em><span data-keyword="lexicographically-smaller-array"><em>lexicographically</em></span><em> largest permutation that is smaller than</em> <code>arr</code>, that can be <strong>made with exactly one swap</strong>. If it cannot be done, then return the same array.</p>
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<p><strong>Note</strong> that a <em>swap</em> exchanges the positions of two numbers <code>arr[i]</code> and <code>arr[j]</code></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> arr = [3,2,1]
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<strong>Output:</strong> [3,1,2]
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<strong>Explanation:</strong> Swapping 2 and 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> arr = [1,1,5]
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<strong>Output:</strong> [1,1,5]
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<strong>Explanation:</strong> This is already the smallest permutation.
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</pre>
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<p><strong class="example">Example 3:</strong></p>
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<pre>
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<strong>Input:</strong> arr = [1,9,4,6,7]
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<strong>Output:</strong> [1,7,4,6,9]
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<strong>Explanation:</strong> Swapping 9 and 7.
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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 <= arr.length <= 10<sup>4</sup></code></li>
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	<li><code>1 <= arr[i] <= 10<sup>4</sup></code></li>
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</ul>
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