Merge Intervals

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

        sort(intervals.begin(), intervals.end(), [](vector<int> a, vector<int>b){

            if(a[0]<b[0]){
                return true;
            }

            return false;

        });


        vector<vector<int>> ans;

        for(int i = 0; i<intervals.size(); i++){

            if(ans.size()==0){
                ans.push_back(intervals[i]);
            }

            else if(ans[ans.size()-1][1] <intervals[i][0]){
                ans.push_back(intervals[i]);
            }

            else{
                ans[ans.size()-1][1] = max(ans[ans.size()-1][1], intervals[i][1]);
            }
        }

        return ans;

    }
};