<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 getIthDigit(int i, int num){
        for(int j=0;j<i;++j) num=num/10;
        return num%10;
    }

    int maximumGap(vector<int>& nums) {
        if(nums.size()<2) return 0;
        vector<vector<int>> bucket;
        for(int i=0;i<10;++i) bucket.push_back(vector<int>());
        for(int i=0;i<=9;++i){
            for(int num: nums){
                int tmp=getIthDigit(i, num);
                bucket[tmp].push_back(num);
            }
            int k=0;
            for(int j=0;j<10;++j){
                for(int num: bucket[j]){
                    nums[k]=num;
                    k+=1;
                }
                bucket[j].clear();
            }
        }
        int ans=nums[1]-nums[0];
        for(int i=1;i<nums.size();++i){
            ans=max(ans, nums[i]-nums[i-1]);
        }
        return ans;
    }
};
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