https://vjudge.net/problem/ZOJ-4025
#include<iostream>
#include<map>
using namespace std;
const int N=1e5+10;
int h[N];
int main()
{
int m,n;
cin>>m;
while(m--)
{
map<int,int> q;
cin>>n;
for(int i=0;i<n;i++)
scanf("%d",&h[i]);
int t;
for(int i=0;i<n;i++)
{
scanf("%d",&t);
q[t-h[i]]++;
}
int ma=0,ans;
for(auto i:q)
{
if(i.second>ma)
ma=i.second;
}
cout<<ma<<"\n";
}
return 0;
}