<p>Given an integer array <code>nums</code> of length <code>n</code> and an integer <code>target</code>, find three integers in <code>nums</code> such that the sum is closest to <code>target</code>.</p>

<p>Return <em>the sum of the three integers</em>.</p>

<p>You may assume that each input would have exactly one solution.</p>

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

<pre>
<strong>Input:</strong> nums = [-1,2,1,-4], target = 1
<strong>Output:</strong> 2
<strong>Explanation:</strong> The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).
</pre>

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

<pre>
<strong>Input:</strong> nums = [0,0,0], target = 1
<strong>Output:</strong> 0
<strong>Explanation:</strong> The sum that is closest to the target is 0. (0 + 0 + 0 = 0).
</pre>

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

<ul>
	<li><code>3 &lt;= nums.length &lt;= 500</code></li>
	<li><code>-1000 &lt;= nums[i] &lt;= 1000</code></li>
	<li><code>-10<sup>4</sup> &lt;= target &lt;= 10<sup>4</sup></code></li>
</ul>

class Solution:
    def threeSumClosest(self, nums: List[int], target: int) -> int:
        nums = sorted(nums)
        closest = sum(nums[:3])

        # calc for each value
        for i, num in enumerate(nums[:-2]):
            # get the left, right indices
            left = i + 1
            right = len(nums) - 1
            while left < right:
                three_sum = num + nums[left] + nums[right]
                if abs(three_sum - target) < abs(closest - target):
                    closest = three_sum

                if three_sum == target:
                    return three_sum
                elif three_sum - target < 0:
                    left += 1
                else:
                    right -= 1

        return closest
16400