Gym - 101853J J - Smallest Difference(尺取法)

J - Smallest Difference

You are given an array a consists of n elements, find the maximum number of elements you can select from the array such that the absolute difference between any two of the chosen elements is  ≤ 1.

Input

The first line contains an integer T (1 ≤ T ≤ 100), in which T is the number of test cases.

The first line of each test case consist of an integer n (2 ≤ n ≤ 104), in which n is size of the array a

The a line follow containing n elements a1, a2, ..., an (1 ≤ ai ≤ 104), giving the arraya.

Output

For each test case, print a single line containing the maximum number of elements you can select from the array such that the absolute difference between any two of the chosen elements is  ≤ 1.

Example

Input

2
3
1 2 3
5
2 2 3 4 5

Output

2
3

 

题意：在给定序列中，挑选出 n 个数，要求这 n 个数任意两个数之间的差的绝对值 小于等于 1， 求 n 最大。

注意  是 挑选 n 个数，不知道有没有和我一样看错题的，以为不能排序，WA了无数发

思路：尺取法，很简单。

AC代码：

#include
using namespace std;

int a[10050];

int main()
{
    int t; scanf("%d",&t);
    while(t--){
        int n; scanf("%d",&n);
        for(int i = 0;i < n;i ++) scanf("%d",&a[i]);
        sort(a,a + n);
        int l = 0,r = 0;
        int maxx = -1;
        int tmp = 0;
        for(int r = 0;r < n;r ++){
            while(a[r] - a[l] > 1){
                l ++;
            }
            maxx = max(maxx,r - l + 1);
        }
        printf("%d\n",maxx);
    }
    return 0;
}