<p>Given an integer array <code>nums</code>, return <em>the maximum difference between two successive elements in its sorted form</em>. If the array contains less than two elements, return <code>0</code>.</p>

<p>You must write an algorithm that runs in linear time and uses linear extra space.</p>

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

<pre>
<strong>Input:</strong> nums = [3,6,9,1]
<strong>Output:</strong> 3
<strong>Explanation:</strong> The sorted form of the array is [1,3,6,9], either (3,6) or (6,9) has the maximum difference 3.
</pre>

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

<pre>
<strong>Input:</strong> nums = [10]
<strong>Output:</strong> 0
<strong>Explanation:</strong> The array contains less than 2 elements, therefore return 0.
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>0 &lt;= nums[i] &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution {
public:
    
    int getDigit(int num, int factor) 
    {
        return (abs(num) / abs(factor)) % 10;
    }
    
    void radixCountingSort(vector<int> &nums, int factor) 
    {
        int freqSize = 10, size = nums.size();
        vector<int> freq(freqSize, 0), sorted(size, 0);
        
        for (int ind = 0; ind < size; ind++)
            freq[getDigit(nums[ind], factor)]++;
        
        for (int ind = 1; ind < freqSize; ind++)
            freq[ind] += freq[ind - 1];
        
        // for stable sorting start ind from end and decrement till 0
        
        for (int ind = size - 1; ind >= 0; ind--) 
            sorted[freq[getDigit(nums[ind], factor)]-- - 1] = nums[ind];
        
        nums = sorted;
    }
    
    void radixSort(vector<int> &nums)
    {
        int minVal = *min_element(nums.begin(), nums.end());
        for(auto &num : nums) 
            num -= minVal;
        
        int factor = 1, maxVal = *max_element(nums.begin(), nums.end());
        
        while (maxVal / factor) 
        {
            radixCountingSort(nums, factor);
            factor *= 10;
        }
        
        for (auto &num : nums) 
            num += minVal;
    }
    
    int maximumGap(vector<int>& nums) 
    {    
        if(nums.size() < 2)
            return 0;
        
        radixSort(nums);
        //sort(nums.begin(), nums.end());
        
        int result = INT_MIN;
        for(int i = 0; i < nums.size() - 1; i++)
            result = max(result, nums[i + 1] - nums[i]);
        return result;
    }
};
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