HPU1009 interval value (value of interval[i,j][i,j]=sum(i,j)∗Check(i,j)=sum(i,j)∗Check(i,j).)

1009: Interval Value of QAQ  [Thinking]

Time Limit: 1 Sec   Memory Limit: 128 MB

enter

Enter an integer T on the first lineT , representing a TT group test data.
Each set of data occupies two lines, the first line input an integer NN , representing the number of elements in the sequence.
Note: 1 < = T<=10000，1<=N<=1000001<=T<=10000，1<=N<=100000。

output

For each set of test data, output the sum of all subinterval values ​​of the sequence.

sample input

3
1
2
99

Sample output

1
0
2500

When N is an even number, the result is zero; when N is an odd number, the result is 1+3+5+...+N. That is, the first item is 1, the tolerance is 2, and the arithmetic difference of (N+1)/2 items in total sequence.

The formula is sorted into (N+1)*(N+1)/4

AC：

#include<iostream>

using namespace std;

int main()
{
int T;
cin>>T;
while(T--)
{
int N;
cin>>N;
if(N&1)
cout<<(N+1)*(N+1)/4<<endl;
else 
cout<<0<<endl;
}
return 0;
}