LYDSY 1041
题目大意
暂无
题目解法
暂无
RTFC
#include <cmath>
#include <cstdio>
inline unsigned gcd(unsigned x, unsigned y)
{
unsigned t;
while (y) t = x % y, x = y, y = t;
return x;
}
unsigned calc(unsigned x)
{
unsigned ret = 0;
for (unsigned i = 1, j; i * i <= x; i++)
{
j = unsigned(sqrt(x - i * i) + 0.5);
if (i >= j) break;
if (i * i + j * j == x && gcd(i, j) == 1) ret++;
}
return ret;
}
int main()
{
unsigned n, ans = 1;
scanf("%u", &n);
n <<= 1;
for (unsigned i = 1; i * i <= n; i++)
if (n % i == 0)
ans += calc(n / i) + (i * i == n ? 0 : calc(i));
printf("%u", ans << 2);
return 0;
}