LeetCode56. 合并区间

:【贪心算法，合并区间有细节！LeetCode：56.合并区间-哔哩哔哩】

class Solution {
public:
    vector<vector<int>> merge(vector<vector<int>>& intervals) {
        if(intervals.size()==0){
            return intervals;
        }
        sort(intervals.begin(),intervals.end());
        vector<vector<int>> ans;
        ans.push_back(intervals[0]);
        for(int i = 1 ;i<intervals.size();++i){
            if(intervals[i][0]<=ans.back()[1]){
                ans.back()[1]=max(intervals[i][1],ans.back()[1]);
            }else{
                ans.push_back(intervals[i]);
            }
        }
        return ans;
    }
};