Activity-Selection

#include<iostream>
#include<algorithm>

class A{
    public:
    int start;
    int finish;
    A(){}
    A(int x,int y):start(x),finish(y){}
};

bool compare(A a, A b){
        return a.finish<b.finish;
}

int main()
{
	int T;
	std::cin>>T;
	while(T--){
	    int n;
	    std::cin>>n;
	    A a[n];
	    for(int i=0;i<n;++i){
	        std::cin>>a[i].start;
	    }
	    for(int i=0;i<n;++i){
	        std::cin>>a[i].finish;
	    }
	    
	    std::sort(a,a+n,compare);
	    
	   // for(int i=0;i<n;++i){
	   //     std::cout<<a[i].start<<" "<<a[i].finish<<"\n";
	   // }
	    
	    int count=1,max=1;
	    int s = a[0].finish;
	    for(int i=1;i<n;++i){
	        if(s<=a[i].start && s<=a[i].finish){
	           // std::cout<<a[i].start<<" "<<a[i].finish<<"\n";
	            count++;
	            if(count>max)
	            max= count;
	            s = a[i].finish;
	        }
	    }
	    std::cout<<max<<"\n";
	}
}