hdu 4627 The Unsolvable Problem

http://acm.hdu.edu.cn/showproblem.php?pid=4627

分类讨论一下就可以

代码：

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<string>
#include<cstring>
#include<cmath>
#include<set>
using namespace std;

typedef long long ll;
typedef pair<double,double>ppd;
const double PI = acos(-1.);
const double eps = (1e-9);
const int N=2005;
const int M=2000000;
const int K=27;

int main()
{
    //freopen("data.in","r",stdin);
    int T;
    scanf("%d",&T);
    while(T--)
    {
       ll n;
       cin>>n;
       if(n==2)
       {cout<<"1"<<endl;continue;}
       ll a=n/2;
       ll b=n-a;
       if(a!=b)
       {cout<<(a*b)<<endl;continue;}
       if((a&1)==0)
       {cout<<(a-1)*(a+1)<<endl;continue;}
       cout<<(a-2)*(a+2)<<endl;
    }
    return 0;
}