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42 lines
1.3 KiB
HTML
42 lines
1.3 KiB
HTML
<p>You are given a positive integer <code>num</code> consisting only of digits <code>6</code> and <code>9</code>.</p>
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<p>Return <em>the maximum number you can get by changing <strong>at most</strong> one digit (</em><code>6</code><em> becomes </em><code>9</code><em>, and </em><code>9</code><em> becomes </em><code>6</code><em>)</em>.</p>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<pre>
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<strong>Input:</strong> num = 9669
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<strong>Output:</strong> 9969
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<strong>Explanation:</strong>
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Changing the first digit results in 6669.
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Changing the second digit results in 9969.
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Changing the third digit results in 9699.
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Changing the fourth digit results in 9666.
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The maximum number is 9969.
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</pre>
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<p><strong>Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> num = 9996
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<strong>Output:</strong> 9999
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<strong>Explanation:</strong> Changing the last digit 6 to 9 results in the maximum number.
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</pre>
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<p><strong>Example 3:</strong></p>
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<pre>
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<strong>Input:</strong> num = 9999
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<strong>Output:</strong> 9999
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<strong>Explanation:</strong> It is better not to apply any change.
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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 <= num <= 10<sup>4</sup></code></li>
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<li><code>num</code> consists of only <code>6</code> and <code>9</code> digits.</li>
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</ul>
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