这是什么意思
For how many positive integers at most N is the product of the digits at most K ?
样例:N=13,K=2,ans=5N=13,K=2,ans=5N=13,K=2,ans=5
解释:
Out of the positive integers at most 13 , there are five such that the product of the digits is at most 2: 1, 2, 10, 11, and 12.