1<=N<=10^9
思路
总结:
程序:
import math
a=math.log(10**9,3)#幂运算和log函数
a=math.ceil(a)#向上取整math.ceil(num)和向下取整math.floor(num)
#求解N范围内的3的幂的整数,题目已经说明1<=N<=10^9
set_three=[]
for i in range(a+1):
b=str(3**i)
# print(type(b))
# print(str(b),b)
b=sorted(str(b))
#print(b)
set_three.append("".join(b))
def solution(n):
n=sorted(str(n))
n="".join(n)
if n in set_three:
return 1
else:
return 0
print(solution(27))