Maximum Gap

Given an unsorted array, find the maximum difference between the successive elements in its sorted form.

Try to solve it in linear time/space.

Return 0 if the array contains less than 2 elements.

You may assume all elements in the array are non-negative integers and fit in the 32-bit signed integer range.

class Solution {public:    int maximumGap(vector<int>& nums) {        int n = nums.size();    if (n < 2)    {    return 0;    }    int maxVal = nums[0];    int minVal = nums[0];    for (int i = 1; i < n; i++)    {    if (nums[i] > maxVal)    {    maxVal = nums[i];    }    else if (nums[i] < minVal)    {    minVal = nums[i];    }    }    int bucketSize = max(1, (maxVal-minVal)/(n-1));//桶排序    int bucketNum = (maxVal-minVal)/bucketSize + 1;    int counter[bucketNum];    int maxElement[bucketNum];    int minElement[bucketNum];    for (int i = 0; i < bucketNum; i++)    {    counter[i] = 0;    maxElement[i] = minVal;    minElement[i] = maxVal;    }    for (int i = 0; i < n; i++)    {    int id = (nums[i]-minVal)/bucketSize;    counter[id]++;    if (nums[i] > maxElement[id])    {    maxElement[id] = nums[i];    }    if (nums[i] < minElement[id])    {    minElement[id] = nums[i];    }    }    int prevMax = minVal;    int result = 0;    for (int i = 0; i < bucketNum; i++)    {    if (counter[i] > 0)    {    int temp = minElement[i] - prevMax;    if (temp > result)    {    result = temp;     }    prevMax = maxElement[i];    }    }    return result;    }};