ZOJ.3175 Number of Containers【数学问题】 2015/10/11

Number of Containers

Time Limit: 1 Second
Memory Limit: 32768 KB

For two integers m and k, k is said to be a container of
m if k is divisible by m. Given 2 positive integers
n and m (m < n), the function f(n, m) is defined to be the number of containers of
m which are also no greater than n. For example, f(5, 1)=4, f(8, 2)=3, f(7, 3)=1, f(5, 4)=0...

Let us define another function F(n) by the following equation:



Now given a positive integer n, you are supposed to calculate the value of F(n).

Input

There are multiple test cases. The first line of input contains an integer
T(T<=200) indicating the number of test cases. Then T test cases follow.

Each test case contains a positive integer n (0 < n <= 2000000000) in a single line.

Output

For each test case, output the result F(n) in a single line.

Sample Input

2
1
4

Sample Output

0
4

Author: CAO, Peng

Source: The 9th Zhejiang University Programming Contest

有点摸不着头脑，不是很懂(｡･∀･)ﾉﾞ

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>

using namespace std;

int main(){
long long n,ans,t,i;
cin>>t;
while(t--){
cin>>n;
ans = 0;
for( i = 1 ; i*i <= n ; ++i ){
ans += n/i;
}
ans *= 2;
i--;
ans = ans - i*i-n;
cout<<ans<<endl;
}
return 0;
}