mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-11-04 11:43:12 +08:00
48 lines
1.7 KiB
HTML
48 lines
1.7 KiB
HTML
<p>You are given a <strong>0-indexed</strong> integer array <code>nums</code> and an integer <code>k</code>.</p>
|
|
|
|
<p>Return <em>an integer that denotes the <strong>sum</strong> of elements in </em><code>nums</code><em> whose corresponding <strong>indices</strong> have <strong>exactly</strong> </em><code>k</code><em> set bits in their binary representation.</em></p>
|
|
|
|
<p>The <strong>set bits</strong> in an integer are the <code>1</code>'s present when it is written in binary.</p>
|
|
|
|
<ul>
|
|
<li>For example, the binary representation of <code>21</code> is <code>10101</code>, which has <code>3</code> set bits.</li>
|
|
</ul>
|
|
|
|
<p> </p>
|
|
<p><strong class="example">Example 1:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> nums = [5,10,1,5,2], k = 1
|
|
<strong>Output:</strong> 13
|
|
<strong>Explanation:</strong> The binary representation of the indices are:
|
|
0 = 000<sub>2</sub>
|
|
1 = 001<sub>2</sub>
|
|
2 = 010<sub>2</sub>
|
|
3 = 011<sub>2</sub>
|
|
4 = 100<sub>2
|
|
</sub>Indices 1, 2, and 4 have k = 1 set bits in their binary representation.
|
|
Hence, the answer is nums[1] + nums[2] + nums[4] = 13.</pre>
|
|
|
|
<p><strong class="example">Example 2:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> nums = [4,3,2,1], k = 2
|
|
<strong>Output:</strong> 1
|
|
<strong>Explanation:</strong> The binary representation of the indices are:
|
|
0 = 00<sub>2</sub>
|
|
1 = 01<sub>2</sub>
|
|
2 = 10<sub>2</sub>
|
|
3 = 11<sub>2
|
|
</sub>Only index 3 has k = 2 set bits in its binary representation.
|
|
Hence, the answer is nums[3] = 1.
|
|
</pre>
|
|
|
|
<p> </p>
|
|
<p><strong>Constraints:</strong></p>
|
|
|
|
<ul>
|
|
<li><code>1 <= nums.length <= 1000</code></li>
|
|
<li><code>1 <= nums[i] <= 10<sup>5</sup></code></li>
|
|
<li><code>0 <= k <= 10</code></li>
|
|
</ul>
|