56. Merge Intervals(56. 合并区间

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Given a collection of intervals, merge all overlapping intervals.

Example 1:

Input: [[1,3],[2,6],[8,10],[15,18]]
Output: [[1,6],[8,10],[15,18]]
Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6].

Example 2:

Input: [[1,4],[4,5]]
Output: [[1,5]]
Explanation: Intervals [1,4] and [4,5] are considered overlapping.

class Solution:
    def merge(self, intervals: List[List[int]]) -> List[List[int]]:
        intervals = sorted(intervals,key=lambda x:x[0])
        print(intervals)
        res = [intervals[0]]
        for ii in intervals[1:]:
            if ii[0] <= res[-1][1]:
                res[-1][1] = max(res[-1][1],ii[1])
            else:
                res.append(ii)
        return res 

 

class Solution {
public:
    vector<vector<int>> merge(vector<vector<int>>& intervals) {
        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;
    }
};