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52 lines
1.6 KiB
HTML
52 lines
1.6 KiB
HTML
<p>Given two integers <code>num</code> and <code>k</code>, consider a set of positive integers with the following properties:</p>
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<ul>
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<li>The units digit of each integer is <code>k</code>.</li>
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<li>The sum of the integers is <code>num</code>.</li>
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</ul>
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<p>Return <em>the <strong>minimum</strong> possible size of such a set, or </em><code>-1</code><em> if no such set exists.</em></p>
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<p>Note:</p>
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<ul>
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<li>The set can contain multiple instances of the same integer, and the sum of an empty set is considered <code>0</code>.</li>
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<li>The <strong>units digit</strong> of a number is the rightmost digit of the number.</li>
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</ul>
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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> num = 58, k = 9
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<strong>Output:</strong> 2
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<strong>Explanation:</strong>
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One valid set is [9,49], as the sum is 58 and each integer has a units digit of 9.
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Another valid set is [19,39].
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It can be shown that 2 is the minimum possible size of a valid set.
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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> num = 37, k = 2
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<strong>Output:</strong> -1
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<strong>Explanation:</strong> It is not possible to obtain a sum of 37 using only integers that have a units digit of 2.
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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> num = 0, k = 7
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<strong>Output:</strong> 0
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<strong>Explanation:</strong> The sum of an empty set is considered 0.
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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>0 <= num <= 3000</code></li>
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<li><code>0 <= k <= 9</code></li>
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</ul>
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