题意：
It's Karaoke time! DreamGrid is performing the song Powder Snow in the game King of Karaoke. The song performed by DreamGrid can be considered as an integer sequence , and the standard version of the song can be considered as another integer sequence . The score is the number of integers satisfying and .
As a good tuner, DreamGrid can choose an integer (can be positive, 0, or negative) as his tune and add to every element in . Can you help him maximize his score by choosing a proper tune?
Input
There are multiple test cases. The first line of the input contains an integer (about 100), indicating the number of test cases. For each test case:
The first line contains one integer (), indicating the length of the sequences and .
The second line contains integers (), indicating the song performed by DreamGrid.
The third line contains integers (), indicating the standard version of the song.
It's guaranteed that at most 5 test cases have .
Output
For each test case output one line containing one integer, indicating the maximum possible score.
Sample Input
2
4
1 2 3 4
2 3 4 6
5
-5 -4 -3 -2 -1
5 4 3 2 1
Sample Output
3
1
Hint
For the first sample test case, DreamGrid can choose and changes to .
For the second sample test case, no matter which DreamGrid chooses, he can only get at most 1 match.
分析：给两个数组，作差求差的众数。该众数可以与题干上说的那个magic数字进行调整，即为得分，刚开始的思路是做桶，但是数组下标不能为负数，需要整体把负数域搬到正数轴上，所以干脆利用map<int,int>偷懒。
#include <iostream>
#include <algorithm>
#include <map>
#include <vector>
#include <cstring>
using namespace std;
typedef long long LL;
int arr[100000];
//int bucket[1000000];
map<int, int> mapp;
int max(int x, int y) { return x >= y ? x : y; }
int main()
{
int T;
cin >> T;
while (T--)
{
memset(arr, 0, sizeof(arr));
mapp.clear();
int n;
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> arr[i];
}
int temp = 0;
for (int i = 0; i < n; i++)
{
cin >> temp;
mapp[arr[i] - temp]++;
}
int maxx = -1;
for (auto i : mapp)
{
maxx = max(i.second, maxx);
}
cout << maxx << endl;
}
return 0;
}