ssu 499 Greatest Greatest Common Divisor

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <map>
#include <cmath>
#include <queue>
#include <cstring>
#include <set>
#include <stack>
#include <string>
#define LL long long
#define maxn 100010
#define mod 1000000007
#define INF 2000000
#define MAX 16000010
#define eps 1e-6
using namespace std;

bool vi[maxn*10] ;
int Max ;
int max(int a ,int b){ return a > b ? a : b ;}

void insert( int n )
{
    int m ,i ,k ;
    m = sqrt(n+0.5) ;
    for( i = 1 ; i <= m ;i++)if(n%i == 0)
    {
        k = n/i ;
        if(vi[i])
        {
            Max = max(Max,i) ;
        }
        else vi[i] = true ;
        if(vi[k]&&k != i)
        {
            Max = max(Max,k) ;
        }
        else vi[k] = true ;
    }
}
int main()
{
    int i ,m , tt , j , n ;
    int L , R , mid ;
    // freopen("in.txt","r",stdin) ;
   // 枚举每个数的因子是可以过的  
    while( scanf("%d",&n) != EOF)
    {
        memset(vi,0,sizeof(vi)) ;
         Max = 0 ;
         for( i = 1 ; i <= n ;i++ ){
             scanf("%d",&m) ;
             insert(m) ;
         }
        printf("%d\n",Max) ;
    }
    return 0 ;
}