7 lines
130 B
C++
7 lines
130 B
C++
ll f(int n)
|
|
{
|
|
ll ans = 0;
|
|
for(int i = 1; i <= n; i = n/(n/i)+ 1)
|
|
ans += (ll)(n/(n/i)-i+1)*(n/i);
|
|
return ans;
|
|
} |