https://programmercarl.com/0056.%E5%90%88%E5%B9%B6%E5%8C%BA%E9%97%B4.html

1.本题和前面几个题的思路大体相同，基本上就是判断是否符合题意，然后进行更新操作。

CPP

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