56. Merge Intervals.md

class Solution {
public:
    vector<vector<int>> merge(vector<vector<int>>& intervals) {
        vector<vector<int>> ans;
        
        sort(intervals.begin(), intervals.end(), [](vector<int> a, vector<int> b) {
            return a[0] < b[0];
        });
        
        ans.push_back(intervals[0]);
        
        for (int i = 1; i < intervals.size(); ++i) {
            if (ans.back()[1] < intervals[i][0]) {
                ans.push_back(intervals[i]);
            } else {
                ans.back()[1] = max(ans.back()[1], intervals[i][1]);
            }
        }
        
        return ans;
    }
};