<p>You are given a <strong>0-indexed</strong> integer array <code>nums</code>. In one operation, you may do the following:</p> <ul> <li>Choose <strong>two</strong> integers in <code>nums</code> that are <strong>equal</strong>.</li> <li>Remove both integers from <code>nums</code>, forming a <strong>pair</strong>.</li> </ul> <p>The operation is done on <code>nums</code> as many times as possible.</p> <p>Return <em>a <strong>0-indexed</strong> integer array </em><code>answer</code><em> of size </em><code>2</code><em> where </em><code>answer[0]</code><em> is the number of pairs that are formed and </em><code>answer[1]</code><em> is the number of leftover integers in </em><code>nums</code><em> after doing the operation as many times as possible</em>.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> nums = [1,3,2,1,3,2,2] <strong>Output:</strong> [3,1] <strong>Explanation:</strong> Form a pair with nums[0] and nums[3] and remove them from nums. Now, nums = [3,2,3,2,2]. Form a pair with nums[0] and nums[2] and remove them from nums. Now, nums = [2,2,2]. Form a pair with nums[0] and nums[1] and remove them from nums. Now, nums = [2]. No more pairs can be formed. A total of 3 pairs have been formed, and there is 1 number leftover in nums. </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> nums = [1,1] <strong>Output:</strong> [1,0] <strong>Explanation:</strong> Form a pair with nums[0] and nums[1] and remove them from nums. Now, nums = []. No more pairs can be formed. A total of 1 pair has been formed, and there are 0 numbers leftover in nums. </pre> <p><strong>Example 3:</strong></p> <pre> <strong>Input:</strong> nums = [0] <strong>Output:</strong> [0,1] <strong>Explanation:</strong> No pairs can be formed, and there is 1 number leftover in nums. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= nums.length <= 100</code></li> <li><code>0 <= nums[i] <= 100</code></li> </ul>