NKABD - Số phong phú
Tác giả: skyvn97
Ngôn ngữ: C++
#include<stdio.h>
#define MAX 100005
typedef unsigned long long ull;
ull s[MAX+10];
ull i,l,r,n;
void init(void)
{
ull i,j;
for (i=1;i*2<=MAX;i=i+1)
for (j=i*2;j<=MAX;j=j+i) s[j]=s[j]+i;
}
int main(void)
{
init();
scanf("%llu",&l);
scanf("%llu",&r);
n=0;
for (i=l;i<=r;i=i+1)
if (s[i]>i) n++;
printf("%llu",n);
return 0;
}