Activity selection problem using Greedy approach

activity.cpp

#include<iostream>
#include<utility>
#include<vector>
#include<algorithm>
using namespace std;
bool myfun(pair<int,int> a ,pair<int,int> b)
{
      return a.second < b.second;	
}
void getActivities(vector< pair<int,int> > a)
{
	sort(a.begin(),a.end(),myfun);
	int i=0;
	cout<<a[0].first<<"--"<<a[0].second<<" "<<endl;
	for(int j=1;j<a.size();j++)
	{
		if(a[j].first>=a[i].second)
		{
			cout<<a[j].first<<"--"<<a[j].second<<" "<<endl;
			i=j;
		}
	}
}
int main()
{
	vector<pair <int,int> > a;
	pair<int,int> p;
	cout<<"Enter No of Activities:"<<endl;
	int n,st,ed;
	cin>>n;
	cout<<"Enter Activities:"<<endl;
	for(int i=0;i<n;i++)
	{
		cin>>st>>ed;
		p.first=st;
		p.second=ed;
		a.push_back(p);
	}
	getActivities(a);
	return 0;
}