LeetCode-57. 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:

Input: intervals = [[1,3],[6,9]], newInterval = [2,5]
Output: [[1,5],[6,9]]

Example 2:

Input: intervals = [[1,2],[3,5],[6,7],[8,10],[12,16]], newInterval = [4,8]
Output: [[1,2],[3,10],[12,16]]
Explanation: Because the new interval [4,8]overlaps with [3,5],[6,7],[8,10].

NOTE: input types have been changed on April 15, 2019. Please reset to default code definition to get new method signature.

题解：

之前想太复杂了，只需要每次更新有交集的数对左右值就ok。

class Solution {
public:
  vector<vector<int>> insert(vector<vector<int>>& intervals, vector<int>& newInterval) {
    int n = intervals.size();
    if (n == 0) {
      return {newInterval};
    }
    vector<vector<int>> res;
    int i = 0;
    while (i < n) {
      if (newInterval[1] < intervals[i][0]) {
        res.push_back(newInterval);
        while (i < n) {
          res.push_back(intervals[i]);
          i++;
        }
        return res;
      }
      else if (newInterval[0] > intervals[i][1]) {
          res.push_back(intervals[i]);
      }
      else {
        newInterval[0] = min(newInterval[0], intervals[i][0]);
        newInterval[1] = max(newInterval[1], intervals[i][1]);
      }
      i++;
    }
    res.push_back(newInterval);
    return res;
  }
};