<p>You have <code>k</code> lists of sorted integers in <strong>non-decreasing&nbsp;order</strong>. Find the <b>smallest</b> range that includes at least one number from each of the <code>k</code> lists.</p>

<p>We define the range <code>[a, b]</code> is smaller than range <code>[c, d]</code> if <code>b - a &lt; d - c</code> <strong>or</strong> <code>a &lt; c</code> if <code>b - a == d - c</code>.</p>

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

<pre>
<strong>Input:</strong> nums = [[4,10,15,24,26],[0,9,12,20],[5,18,22,30]]
<strong>Output:</strong> [20,24]
<strong>Explanation: </strong>
List 1: [4, 10, 15, 24,26], 24 is in range [20,24].
List 2: [0, 9, 12, 20], 20 is in range [20,24].
List 3: [5, 18, 22, 30], 22 is in range [20,24].
</pre>

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

<pre>
<strong>Input:</strong> nums = [[1,2,3],[1,2,3],[1,2,3]]
<strong>Output:</strong> [1,1]
</pre>

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

<ul>
	<li><code>nums.length == k</code></li>
	<li><code>1 &lt;= k &lt;= 3500</code></li>
	<li><code>1 &lt;= nums[i].length &lt;= 50</code></li>
	<li><code>-10<sup>5</sup> &lt;= nums[i][j] &lt;= 10<sup>5</sup></code></li>
	<li><code>nums[i]</code>&nbsp;is sorted in <strong>non-decreasing</strong> order.</li>
</ul>

class Solution:
    def smallestRange(self, nums):
        arr = []
        
        for i in range(len(nums)):
            for j in range(len(nums[i])):
                arr.append((nums[i][j], i))
        arr.sort()
        
        j = 0
        res = []
        count = defaultdict(int)
        total = 0
        diff = len(nums)
        minV = float('inf')

        for i in range(len(arr)):
            count[arr[i][1]] += 1
            if count[arr[i][1]] == 1:
                total += 1

            if diff == total:
                if arr[i][0] - arr[j][0] + 1 < minV:
                    minV = arr[i][0] - arr[j][0] + 1
                    res = [arr[j][0], arr[i][0]]

            while diff == total:
                if count[arr[j][1]] > 1:
                    count[arr[j][1]] -= 1
                    j += 1
                else:
                    break
                if arr[i][0] - arr[j][0] + 1 < minV:
                    minV = arr[i][0] - arr[j][0] + 1
                    res = [arr[j][0], arr[i][0]]
        
        return res
24700