
ZOJ Problem Set  2286
For an integer n, define f(n) to be the sum of its proper divisors (the divisors excluding the number itself), f is called the restricted divisor function. Given an integer m. Find how many integers n between 1 and 1000000 (inclusively) has f(n)<=m.
Author: PAN, Minghao Source: ZOJ Monthly, January 2005 