【细节实现题】LeetCode 57. Insert Interval

LeetCode 57. Insert Interval

Solution1：我的答案
算法很简单，不知道为何会被标记为hard题目

/**
 * 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:
    vector<Interval> insert(vector<Interval>& intervals, Interval newInterval) {
        vector<Interval> res;
        int i = 0;
        // pre
        for (; i < intervals.size(); i++) {
            if (intervals[i].end < newInterval.start) {
                res.push_back(intervals[i]);
            } else
                break;
        }
        int new_start = newInterval.start, new_end = newInterval.end;
        for (; i < intervals.size(); i++) {
            if (!(newInterval.start > intervals[i].end 
                || newInterval.end < intervals[i].start)) {
                new_start = min(new_start, intervals[i].start);
                new_end = max(new_end, intervals[i].end);
            } else
                break;
        }
        Interval temp = Interval(new_start, new_end);
        res.push_back(temp);
        //post
        for (; i < intervals.size(); i++) 
            res.push_back(intervals[i]);
        return res;
    }
};