SCU 4489 misaka and last order（暴力枚举）

misaka and last order

Description

Misaka Mikoto is a main character of the Animation "To Aru Majutsu no Index" and "To Aru Kagaku no Railgun".
She was enrolled into the Academy City to train herself and had been working very hard until she was ranked Level 5,
which is regarded as the highest ranking around the city.
By the way, there are only seven people who reached that level, and she won the third place. Now, she is the best "Electromaster" in Academy City.
Mikoto's unique skill is to shoot metal objects such as coins at a high speed, destructively.
Hence, she finally gained a nickname, "Railgun" (超電磁砲 (レールガン) .
Mikoto attended Tokiwadai Middle School,which is a famous girls' secondary school for the rich and elites and was acknowledged
as one of the five famous schools in the Academy City.
To most people, she is considered a typical lady, but in reality, she is short-tempered, prideful, and greatly interested in some childish things.

Misaka has many sisters, they are Misaka's clones. Unlike Mikoto, they seem rather quiet and emotionless,
their voices are rather monotonous and computer-like, and they speak in third person by adding a description of themselves after every sentence.
In addition, they wear a special set of goggles that enables them to see electron beams and magnetic field lines for the reason that,
unlike Mikoto, they do not have that ability. Misaka clone No. 20001(Last order, 打ち止め, 最终之作).
She is the administrator of the Misaka Network and the fail-safe mechanism in case the Sisters go out of control.
She is not designed to function independently and survive for long outside a culture container and appears to be only about ten years old.

Misaka finds that all her sisters were trapped in a laboratory. Accelerator(一方通行 ,アクセラレータ) is going to kill them!!
She must take actions to save them. Last order tells her that she may not take all the sisters away.
Each sister has an electronic value a. If the GCD(Greatest Common Divisor) of some sisters’ value is greater than m
(if only one sister was chosen, the GCD is the electronic value of herself), then these sisters can be taken away.
Misaka wants to save as many sisters as possible. Please help her!!

Input

In the first line, there is an integer T, indicating the number of test cases.

The next T cases follow. For the first line, there are two integer n and m, n is the number of the sisters, m is the GCD limit.(1 <= n, m <= 1000000)

Then another line shows n integer, represents all the electronic values of al
d5dd
l the sisiters.(1 <= values <= 1000000)

Output

Output one line for each test case.

Just print the max number of sisters which Misaka can save.

Sample Input

3
3 1
1 2 3
3 2
1 2 4
3 4
1 3 5

Sample Output

3
2
1

Hint

For the third case, Misaka can only choose the third sister.

原题链接：http://acm.scu.edu.cn/soj/problem.action?id=4489

ps：虽然是最后还剩十几分钟了才做这道题，但是还是把它想的太复杂了

直接从m开始枚举到最大数，判断m的倍数在数组中出现几次，最后把次数加起来即可

代码：

#include<stdio.h>
#include<string.h>

#define max(a,b) (a>b?a:b)
#define maxn 1000000+10
int vis[maxn];

int main()
{
int t;
scanf("%d",&t);
while(t--)
{
memset(vis,0,sizeof(vis));
int n,m,maxx=0,a;
scanf("%d%d",&n,&m);
for(int i=0; i<n; i++)
{
scanf("%d",&a);
vis[a]++;
maxx=max(maxx,a);
}
int ans=0;
for(int i=m; i<=maxx; i++)
{
int cnt=0;
for(int j=1; j<=maxx; j++)
{
int temp=i*j;
if(temp>maxx)
break;
cnt+=vis[temp];
}
ans=max(cnt,ans);
}
printf("%d\n",ans);
}
return 0;
}