HDU 5429-Geometric Progression(JAVA大数判断等比数列)

import java.util.*;
import java.math.*;

public class Main {
public static void main(String[] args) {
BigDecimal[] x = new BigDecimal[110];
BigDecimal a,b;
int T,n,i;
int flag;
int cnt;
Scanner cin=new Scanner(System.in);
T=cin.nextInt();
while (T-->0){
n=cin.nextInt();
flag=cnt=0;
for (i=0; i<n; i++){
x[i] = cin.nextBigDecimal();
if (x[i].compareTo(BigDecimal.valueOf(0))==0)
cnt++;
}
if (n==1){
System.out.println("Yes");
continue;
}
if (cnt!=0){
if(cnt==n)
System.out.println("Yes");
else
System.out.println("No");
continue;
}
for (i=1; i<n-1; i++){
a=x[i].multiply(x[i]);
b=x[i-1].multiply(x[i+1]);
if (a.compareTo(b)!=0){
flag=1;
break;
}
}
if (flag==0)
System.out.println("Yes");
else
System.out.println("No");
}
}

}