57. Insert Interval(插入区间)

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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].

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 左边不重叠： a[i][1] < new[0]

 右边不重叠：  a[i][0] > new[1] ---取反-->中间重叠 a[i][0] <= new[1]

 

 

class Solution:
    def insert(self, intervals: List[List[int]], newInterval: List[int]) -> List[List[int]]:
        i = 0 
        res = []
        n = len(intervals)
        while i < n and intervals[i][1] < newInterval[0]:
            res.append(intervals[i])
            i+=1
        while i < n and intervals[i][0] <= newInterval[1]:
            newInterval[0] = min(newInterval[0],intervals[i][0])
            newInterval[1] = max(newInterval[1],intervals[i][1])
            i+=1
        res.append(newInterval)
        while i < n :
            res.append(intervals[i])
            i+=1
        return res

 

 

 

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

 

 

 

 

 

 

 把要插入的元素插入，然后调用上一个题的merge

 

class Solution {
public:
    vector<vector<int>> insert(vector<vector<int>>& intervals, vector<int>& newInterval) {
        intervals.emplace_back(newInterval);
        sort(intervals.begin(),intervals.end());
        int s = 0, f = 0;
        vector<vector<int>> res;
        res.emplace_back(intervals[0]);
        for(int f = 1; f < intervals.size();f++) {
            auto& cur_node = res.back();
            if (intervals[f][0] <= cur_node[1]) {
                cur_node[1] = max(cur_node[1],intervals[f][1]);
            } else {
                res.emplace_back(intervals[f]);
            }
        }
        return res;

    }
};