Leetcode: Insert Interval

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).

You may assume that the intervals were initially sorted according to their start times.

Example 1:
Given intervals [1,3],[6,9], insert and merge [2,5] in as [1,5],[6,9].

Example 2:
Given [1,2],[3,5],[6,7],[8,10],[12,16], insert and merge [4,9] in as [1,2],[3,10],[12,16].

This is because the new interval [4,9] overlaps with [3,5],[6,7],[8,10].

需要细心，虽然不难。用一个辅助数组会简单些，二分查找也增加了点难度。

/** * 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) {        int mid, low = 0, up = intervals.size() - 1;        while (low <= up) {            mid = (low + up) / 2;            if (intervals[mid].start < newInterval.start) {                low = mid + 1;            }            else if (intervals[mid].start > newInterval.start) {                up = mid - 1;            }            else {                low = mid + 1;                break;            }        }                // low points to the inserted position        --low;        if (low < 0) {            intervals.insert(intervals.begin(), newInterval);            low = 0;        }        else {            if (intervals[low].end < newInterval.start) {                ++low;                intervals.insert(intervals.begin() + low, newInterval);            }            else {                intervals[low].end = max(intervals[low].end, newInterval.end);            }        }                int i = low + 1;        for (; i < intervals.size(); ++i) {            if (intervals[low].end < intervals[i].start) {                break;            }        }        intervals[low].end = max(intervals[low].end, intervals[i-1].end);        if (i > low + 1) {            intervals.erase(intervals.begin() + low + 1, intervals.begin() + i);        }                return intervals;    }};