bzoj1385 [Baltic2000]Division expression

 1 #include<algorithm>
 2 #include<iostream>
 3 #include<cstdlib>
 4 #include<cstring>
 5 #include<cstdio>
 6 #include<string>
 7 #include<cmath>
 8 #include<ctime>
 9 #include<queue>
10 #include<stack>
11 #include<map>
12 #include<set>
13 #define rre(i,r,l) for(int i=(r);i>=(l);i--)
14 #define re(i,l,r) for(int i=(l);i<=(r);i++)
15 #define Clear(a,b) memset(a,b,sizeof(a))
16 #define inout(x) printf("%d",(x))
17 #define douin(x) scanf("%lf",&x)
18 #define strin(x) scanf("%s",(x))
19 #define LLin(x) scanf("%lld",&x)
20 #define op operator
21 #define CSC main
22 typedef unsigned long long ULL;
23 typedef const int cint;
24 typedef long long LL;
25 using namespace std;
26 void inin(int &ret)
27 {
28     ret=0;int f=0;char ch=getchar();
29     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=1;ch=getchar();}
30     while(ch>=‘0‘&&ch<=‘9‘)ret*=10,ret+=ch-‘0‘,ch=getchar();
31     ret=f?-ret:ret;
32 }
33 int t,a[10010],n;
34 int gcd(int a,int b)
35 {
36     int c;
37     while(a%b)c=a%b,a=b,b=c;
38     return b;
39 }
40 int main()
41 {
42     inin(t);
43     while(t--)
44     {
45         inin(n);
46         re(i,1,n)inin(a[i]);
47         re(i,1,n)if(i!=2)
48         {
49             a[2]/=gcd(a[2],a[i]);
50             if(a[2]==1)break;
51         }
52         if(a[2]==1)puts("YES");
53         else puts("NO");
54     }
55      return 0;
56 }