GCJ 2008Round1AA 菜鸟踩坑（C++）

#include <cstdio>
#include<iostream>
#include <fstream>
#include <algorithm>
using namespace std;
#define MAX 100000

typedef long long ll;

ll x[MAX];
ll y[MAX];
ll res;
bool comp(ll x,ll y)
{
    return x>y;
}

int main()
{
    ofstream out("small_output.txt");
    ifstream in("A-large-practice.in");
    ll loop;
    in>>loop;
    for(ll i=1;i<=loop;i++)
    {
        res=0;
        ll n;
        in>>n;
        cout<<"n = "<<n<<endl;
        cout<<"thie is no."<<i<<" loop"<<endl;
        ll p;
        ll q;
        for(p=0;p<n;p++)
        {
            in>>x[p];
        }
        cout<<"x over!!!! "<<" p= "<<p<<endl;
        for(q=0;q<n;q++)
        {
            in>>y[q];
        }
        cout<<"y over!!!! "<<" q= "<<q<<endl;
        sort(x,x+n,comp);
        sort(y,y+n);
        for(ll q=0;q<n;q++)
        {
            res+=x[q]*y[q];
        }
        out<<"Case #"<<i<<": "<<res<<endl;
        cout<<" case "<<i<<"write done"<<endl;
    }
    out.close();
    return 0;
}