B2029 大象喝水

https://www.luogu.com.cn/record/88083047

Luogu/B2029/B2029.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+#include <cmath>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const double pi = acos(-1);
+
+int h, r;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> h >> r;
+
+    cout << ceil(20000.0 / (pi * r * r * h)) << endl;
+
+    return 0;
+}