UVA11827 Maximum GCD

 /*
  UVA11827 Maximum GCD
  https://vjudge.net/contest/153365#problem/V
  数论 gcd
  水题，然而读入比较坑
  *
  */
 #include <cstdio>
 #include <algorithm>
 #include <cstring>
 #include <cmath>
 #include <vector>
 #include <queue>
 //#define test
 using namespace std;
 const int Nmax=;

 long long gcd(long long a,long long b)
 {
     if(b==0LL)
         return a;
     return gcd(b,a%b);
 }
 long long num[Nmax];

 int read(long long &a)
 {
     long long ans=0LL;
     char c=getchar();
     while(c==' ')
         c=getchar();
     int flag=;
     while(c>='' && c<='')
     {
         flag=;
         ans=ans*10LL+c-'';
         c=getchar();
     }
     if(flag)
     {
         a=1LL;
         return ;
     }
     a=ans;
     if(c=='\n')
     {
         //a=1LL;
         return ;
     }
     return ;
 }

 int main()
 {
     #ifdef test
     freopen("uva.in","r",stdin);
     #endif
     int n;
     scanf("%d",&n);
     getchar();
     while(n--)
     {
         long long mmax=-1LL;
         int m=;
         while(read(num[++m]));
         //for(int i=1;i<=m;i++)
             //printf("%d ",num[i]);
         //printf("\n");
         for(int i=;i<=m;i++)
         {
             for(int j=i+;j<=m;j++)
             {
                 mmax=max(mmax,gcd(num[i],num[j]));
             }
         }
         printf("%lld\n",mmax);
     }
     return ;
 }