Counting Divisors 区间筛做法.将内的素数筛出来,以素数的位置开始往后筛,边记录每个素数对该数的贡献. #include<bits/stdc++.h> #define me(a,x) memset(a,x,sizeof(a)) #define sc scanf #define itn int #define IN freopen("in.txt","r",stdin); #define OUT freopen("out.txt","w",stdout); #define STR clock_t startTime = clock(); #define E...