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52 lines
2.3 KiB
HTML
52 lines
2.3 KiB
HTML
<p>You are given a <strong>0-indexed</strong> array <code>words</code> consisting of <strong>distinct</strong> strings.</p>
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<p>The string <code>words[i]</code> can be paired with the string <code>words[j]</code> if:</p>
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<ul>
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<li>The string <code>words[i]</code> is equal to the reversed string of <code>words[j]</code>.</li>
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<li><code>0 <= i < j < words.length</code>.</li>
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</ul>
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<p>Return <em>the <strong>maximum</strong> number of pairs that can be formed from the array </em><code>words</code><em>.</em></p>
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<p>Note that each string can belong in <strong>at most one</strong> pair.</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> words = ["cd","ac","dc","ca","zz"]
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<strong>Output:</strong> 2
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<strong>Explanation:</strong> In this example, we can form 2 pair of strings in the following way:
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- We pair the 0<sup>th</sup> string with the 2<sup>nd</sup> string, as the reversed string of word[0] is "dc" and is equal to words[2].
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- We pair the 1<sup>st</sup> string with the 3<sup>rd</sup> string, as the reversed string of word[1] is "ca" and is equal to words[3].
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It can be proven that 2 is the maximum number of pairs that can be formed.</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> words = ["ab","ba","cc"]
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<strong>Output:</strong> 1
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<strong>Explanation:</strong> In this example, we can form 1 pair of strings in the following way:
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- We pair the 0<sup>th</sup> string with the 1<sup>st</sup> string, as the reversed string of words[1] is "ab" and is equal to words[0].
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It can be proven that 1 is the maximum number of pairs that can be formed.
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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> words = ["aa","ab"]
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<strong>Output:</strong> 0
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<strong>Explanation:</strong> In this example, we are unable to form any pair of strings.
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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 <= words.length <= 50</code></li>
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<li><code>words[i].length == 2</code></li>
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<li><code>words</code> consists of distinct strings.</li>
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<li><code>words[i]</code> contains only lowercase English letters.</li>
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</ul>
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