description:
Given a collection of intervals, merge all overlapping intervals..
Note:
Example:
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.
answer:
class Solution {
public:
vector<vector<int>> merge(vector<vector<int>>& intervals) {
if (intervals.empty()) return {};
sort(intervals.begin(), intervals.end());
vector<vector<int>> res{intervals[0]};
for (int i = 0; i < intervals.size(); ++i) {
if (res.back()[1] < intervals[i][0]) {
res.push_back(intervals[i]);
} else {
res.back()[1] = max(res.back()[1], intervals[i][1]);
}
}
return res;
}
};