<p>Given a <strong>sorted</strong> integer array <code>arr</code>, two integers <code>k</code> and <code>x</code>, return the <code>k</code> closest integers to <code>x</code> in the array. The result should also be sorted in ascending order.</p>

<p>An integer <code>a</code> is closer to <code>x</code> than an integer <code>b</code> if:</p>

<ul>
	<li><code>|a - x| &lt; |b - x|</code>, or</li>
	<li><code>|a - x| == |b - x|</code> and <code>a &lt; b</code></li>
</ul>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> arr = [1,2,3,4,5], k = 4, x = 3
<strong>Output:</strong> [1,2,3,4]
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> arr = [1,2,3,4,5], k = 4, x = -1
<strong>Output:</strong> [1,2,3,4]
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= k &lt;= arr.length</code></li>
	<li><code>1 &lt;= arr.length &lt;= 10<sup>4</sup></code></li>
	<li><code>arr</code> is sorted in <strong>ascending</strong> order.</li>
	<li><code>-10<sup>4</sup> &lt;= arr[i], x &lt;= 10<sup>4</sup></code></li>
</ul>

class Solution {
public:

    // bound()
    // returns index say 'ind', where nums[ind] <= x
    int bound(vector<int>&nums,int x)
    {
        int low = 0 , high = nums.size() - 1;
        int mid;
        while(low <= high)
        {
            mid = low + (high-low)/2;
            if(nums[mid] == x or nums[mid] < x) low = mid + 1;
            else
                high = mid - 1;   
        }
        return low;
    }

    vector<int> findClosestElements(vector<int>& arr, int k, int x) {
        int ind =  bound(arr,x); // find index where nums[ind] is equal or just less than 'x' 
        int i = ind - 1 , j = ind; // two pointers
        int n = arr.size();
        while(k--)
        {
            if(i >= 0 and j < n)
            {
                // expand i to left 
                if(abs(arr[i] - x) <= abs(arr[j] - x )) 
                    i--;
                else 
                // expand j to right
                    j++;
            }
            else
            if(i < 0)
            {
                j++;
            }
            else
            if(j >= n)
            {
                i--;
            }
        }
    return vector<int>(arr.begin()+i+1,arr.begin()+j);
    }
};
33800