LeetCode-Insert Interval

对于一个排序的non-overlap的Interval集合。插入一个Interval。
遍历插入的情况。思路比较简单，代码如下：

/**
 * Definition for an interval.
 * struct Interval {
 *     int start;
 *     int end;
 *     Interval() : start(0), end(0) {}
 *     Interval(int s, int e) : start(s), end(e) {}
 * };
 */
class Solution {
public:
    bool is_overlap(const Interval& rhs,const Interval& rhl){
        if (rhs.start<=rhl.end && rhs.start>=rhl.start)return true;
        if (rhl.start<=rhs.end && rhl.start>=rhs.start)return true;
        return false;
    }
    Interval mergeTwo(const Interval& inter, Interval& newInterval){
        if (inter.start>=newInterval.start && inter.start<=newInterval.end){
            Interval res;
            res.start = newInterval.start;
            res.end = newInterval.end>inter.end? newInterval.end:inter.end;
            return res;
        }
        if (inter.start<=newInterval.start && inter.end>=newInterval.start){
            Interval res;
            res.start = inter.start;
            res.end = newInterval.end>inter.end? newInterval.end:inter.end;
            return res;
        }
    }
    vector insert(vector& intervals, Interval newInterval) {
        vector res;
        for (const auto& inter:intervals){
            if (is_overlap(inter,newInterval)){
                /*
                
                */
                newInterval = mergeTwo(inter,newInterval);
            }else{
                res.push_back(inter);
            }
        }
        res.push_back(newInterval);
        sort(res.begin(),res.end(),[](const auto& rhs,const auto& rhl){return rhs.end