public static void main(String[] args) {
int i =0;
int shang=0;
int xia=0;
while(i<10) {
System.out.print("请输入你的年龄:");
Scanner input = new Scanner(System.in);
double nian = input.nextDouble();
if(nian>30) {
shang++;
}
if(nian<30){
xia++;
}
i++;
}
System.out.println("两个层次的客户比例是:"+shang+":"+xia);
}