class Solution {public:    int maximumGap(vector<int> &num) {        int len = num.size();        int gap = 0;        sort(num.begin(), num.end());        for (int i=0; i<len-1; i++) {            int cgap = num[i+1] - num[i];            if (cgap > gap) {                gap = cgap;            }        }        return gap;    }};