from time import*
sleep(10)
print("------执行开始------")
a = 10
for i in range(a+1):
    b = (i/a)*100
    c = i*2*'*'
    d = (a-i)*2*'.'
    print("%{:^3.0f}[{}->{}]".format(b,c,d))
print("------执行结束------")