leetcode-problemset/leetcode/problem/sum-of-even-numbers-after-queries.html

<p>You are given an integer array <code>nums</code> and an array <code>queries</code> where <code>queries[i] = [val<sub>i</sub>, index<sub>i</sub>]</code>.</p>

<p>For each query <code>i</code>, first, apply <code>nums[index<sub>i</sub>] = nums[index<sub>i</sub>] + val<sub>i</sub></code>, then print the sum of the even values of <code>nums</code>.</p>

<p>Return <em>an integer array </em><code>answer</code><em> where </em><code>answer[i]</code><em> is the answer to the </em><code>i<sup>th</sup></code><em> query</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3,4], queries = [[1,0],[-3,1],[-4,0],[2,3]]
<strong>Output:</strong> [8,6,2,4]
<strong>Explanation:</strong> At the beginning, the array is [1,2,3,4].
After adding 1 to nums[0], the array is [2,2,3,4], and the sum of even values is 2 + 2 + 4 = 8.
After adding -3 to nums[1], the array is [2,-1,3,4], and the sum of even values is 2 + 4 = 6.
After adding -4 to nums[0], the array is [-2,-1,3,4], and the sum of even values is -2 + 4 = 2.
After adding 2 to nums[3], the array is [-2,-1,3,6], and the sum of even values is -2 + 6 = 4.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [1], queries = [[4,0]]
<strong>Output:</strong> [0]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>4</sup></code></li>
	<li><code>-10<sup>4</sup> &lt;= nums[i] &lt;= 10<sup>4</sup></code></li>
	<li><code>1 &lt;= queries.length &lt;= 10<sup>4</sup></code></li>
	<li><code>-10<sup>4</sup> &lt;= val<sub>i</sub> &lt;= 10<sup>4</sup></code></li>
	<li><code>0 &lt;= index<sub>i</sub> &lt; nums.length</code></li>
</ul>