Description
We know that some positive integer x can be expressed as x=A^2+B^2(A,B are integers). Take x=10 for example,
10=(-3)^2+1^2.
We define R(N) (N is positive) to be the total number of variable presentation of N. So R(1)=4, which consists of 1=1^2+0^2, 1=(-1)^2+0^2, 1=0^2+1^2, 1=0^2+(-1)^2.Given N, you are to calculate R(N).
10=(-3)^2+1^2.
We define R(N) (N is positive) to be the total number of variable presentation of N. So R(1)=4, which consists of 1=1^2+0^2, 1=(-1)^2+0^2, 1=0^2+1^2, 1=0^2+(-1)^2.Given N, you are to calculate R(N).
Input
No more than 100 test cases. Each case contains only one integer N(N<=10^9).
Output
For each N, print R(N) in one line.
Sample Input
2
6
10
25
65
Sample Output
4
0
8
12
16
Hint
For the fourth test case, (A,B) can be (0,5), (0,-5), (5,0), (-5,0), (3,4), (3,-4), (-3,4), (-3,-4), (4,3) , (4,-3), (-4,3), (-4,-3)
1 #include<cstdio> 2 #include<math.h> 3 using namespace std; 4 int main() 5 { 6 int n; 7 while(scanf("%d",&n)!=EOF) 8 { 9 int ans=0; 10 for(int i=1;i*i<=n;i++)//i是平方因子11 { 12 double m=sqrt(n-i*i); 13 if(floor(m+0.50)==m) ans++;//floor这个函数是用来判断m 是否是整数,加0.5是用来减少误差的。 14 } 15 printf("%d\n",4*ans);//每种情况都有四种情况 16 } 17 return 0; 18 }