LightOJ 1245 - Harmonic Number (II)

Analysis Part: 1245 - Harmonic Number (II) Analysis Part

/**
  *  @Author: Pranta Sarker
  *
  **/


#include<bits/stdc++.h>

using namespace std;

#define fast ios_base::sync_with_stdio(0)
#define bfast cin.tie(0)
#define outs(x) cout << x << " "
#define outn(x) cout << x << "\n"
#define sf scanf
#define pf printf
#define pfn(x , k) printf(k , x)
#define nl puts("")
#define psb push_back
#define mset(c,v) memset(c , v , sizeof c)
#define loop0(n) for(int i=0; i<n; i++)
#define loop1(n) for(int i=1; i<=n; i++)
#define mpair(x , y) make_pair(x , y)
#define all(x) x.begin(), x.end()
#define pi acos(-1.0)
#define psb push_back
#define clr clear()

typedef unsigned long long ull;
typedef long long LL;
typedef vector<int>vii;
typedef vector<LL>vll;
typedef vector<string>vs;
typedef map<int, int>mpii;
typedef map<string, int>mpsi;
typedef map<char, int>mpci;
typedef map<LL, LL>mpll;

const int mod = 1000007;
const int high = 10002;

LL H( LL n )
{
    LL i , res = 0;

    for(i=1; i*i<=n; i++)
    {
        res += (n / i);
    }

    i--;

    return res = (res * 2) - (i * i);
}


int main()
{
    fast;
    int test, tcno=0;
    cin >> test;
    while(test--)
    {
        LL N;
        cin >> N;
        cout << "Case " << ++tcno << ": " << H(N) << "\n";
    }

    return 0;
}