activity selection problem time limit error

Question

Im trying to solve the activity selection problem but do not understand how to improve my code to avoid the Time Limit Error (TLE) . Please suggest what went wrong in this simple question .

question : https://www.codingninjas.com/codestudio/problems/1062658?topList=striver-sde-sheet-problems&utm_source=striver&utm_medium=website&leftPanelTab=1

My code :

#include<algorithm>
vector<int> maximumMeetings(vector<int> &start, vector<int> &end) {
    // Write your code here.
    vector<vector<int>> A;
    vector<int> temp ;
    for(int i=0; i<start.size(); i++){
        temp.clear();
        temp.push_back(start[i]);
        temp.push_back(end[i]);
        temp.push_back(i+1);
        A.push_back(temp);
    }
    sort(A.begin(),A.end(),[](vector<int>A,vector<int>B){
        if(A[1]!=B[1]){
            return A[1]<B[1];
        }
        else{
            return A[2]<B[2];
        }
        
    });
    vector<int> ans;
    ans.push_back(A[0][2]);
    int j=0;
    for(int i=1; i<A.size(); i++){
        if(A[i][0]>A[j][1]){
            ans.push_back(A[i][2]);
            j=i;
        }
    }
    return ans ;
}

EDIT 1 : here is the problem copy pasted from the site , as requested in the comments , tho I have not pasted the example test cases to keep it short .

Problem Statement You are given the schedule of N meetings with their start time Start[i] and end time End[i]. But you have only 1 meeting room. So, you need to tell the meeting numbers you can organize in the given room, such that the number of meetings organized is maximum. Note: The start time of one chosen meeting can’t be equal to the end time of the other chosen meeting. Also for the same end time, a meeting with a smaller index is preferred.

The doubt has been solved , I just needed to pass the vector by reference in the lambda comparator function for sort function .