LYDSY 2048
题目大意
暂无
题目解法
暂无
RTFC
#include <cmath>
#include <cstdio>
const double eps = 1e-10, r = 0.5772156649;
typedef long long ll;
int main()
{
double ans;
ll n, m;
ans = n = m = 0;
scanf("%lld%lld", &n, &m);
if (n <= 10000)
for (int i = 1; i <= n; i++)
ans += 0.5 / i;
else
ans = log(n + 1.0) + r, ans /= 2.0;
ans *= m;
printf("%d\n", (int)(ans - eps));
}