#P1850F. We Were Both Children

    ID: 575 远端评测题 3000ms 256MiB 尝试: 26 已通过: 5 难度: 8 上传者: 标签>brute forceimplementationmathnumber theory*1300

We Were Both Children

题面翻译

米哈依和斯拉夫有 nn 只青蛙,每只青蛙初始都在 00 位置,每秒会往前跳 aia_{i} 。你可以在位置 11nn 设置一个陷阱,陷阱会抓住经过它的所有青蛙,请问你最多可以抓住几只青蛙。

题目描述

Mihai and Slavic were looking at a group of n n frogs, numbered from 1 1 to n n , all initially located at point 0 0 . Frog i i has a hop length of ai a_i .

Each second, frog i i hops ai a_i units forward. Before any frogs start hopping, Slavic and Mihai can place exactly one trap in a coordinate in order to catch all frogs that will ever pass through the corresponding coordinate.

However, the children can't go far away from their home so they can only place a trap in the first n n points (that is, in a point with a coordinate between 1 1 and n n ) and the children can't place a trap in point 0 0 since they are scared of frogs.

Can you help Slavic and Mihai find out what is the maximum number of frogs they can catch using a trap?

输入格式

The first line of the input contains a single integer t t ( 1t100 1 \le t \le 100 ) — the number of test cases. The description of test cases follows.

The first line of each test case contains a single integer n n ( 1n2105 1 \leq n \leq 2 \cdot 10^5 ) — the number of frogs, which equals the distance Slavic and Mihai can travel to place a trap.

The second line of each test case contains n n integers a1,,an a_1, \ldots, a_n ( 1ai109 1 \leq a_i \leq 10^9 ) — the lengths of the hops of the corresponding frogs.

It is guaranteed that the sum of n n over all test cases does not exceed 2105 2 \cdot 10^5 .

输出格式

For each test case output a single integer — the maximum number of frogs Slavic and Mihai can catch using a trap.

样例 #1

样例输入 #1

7
5
1 2 3 4 5
3
2 2 2
6
3 1 3 4 9 10
9
1 3 2 4 2 3 7 8 5
1
10
8
7 11 6 8 12 4 4 8
10
9 11 9 12 1 7 2 5 8 10

样例输出 #1

3
3
3
5
0
4
4

提示

In the first test case, the frogs will hop as follows:

  • Frog 1: $ 0 \to 1 \to 2 \to 3 \to \mathbf{\color{red}{4}} \to \cdots $
  • Frog 2: $ 0 \to 2 \to \mathbf{\color{red}{4}} \to 6 \to 8 \to \cdots $
  • Frog 3: 036912 0 \to 3 \to 6 \to 9 \to 12 \to \cdots
  • Frog 4: $ 0 \to \mathbf{\color{red}{4}} \to 8 \to 12 \to 16 \to \cdots $
  • Frog 5: 05101520 0 \to 5 \to 10 \to 15 \to 20 \to \cdots

Therefore, if Slavic and Mihai put a trap at coordinate 4 4 , they can catch three frogs: frogs 1, 2, and 4. It can be proven that they can't catch any more frogs.In the second test case, Slavic and Mihai can put a trap at coordinate 2 2 and catch all three frogs instantly.