10209 solved

10209.cpp

@@ -0,0 +1,29 @@
+#include <iostream>
+#include <cmath>
+#include <iomanip>
+using namespace std;
+
+int main(void) {
+    double a;
+    double PI = 2 * acos(0);
+
+    while (cin >> a) {
+
+        if (a == 0) {
+            cout << "0.000 0.000 0.000" << endl;
+            continue;
+        }
+
+        double x = a / 2;
+
+        double tmp = 0.5 * (x * sqrt(a * a - x * x) + a * a * atan(x / sqrt(a * a - x * x)));
+
+        double checkered = (a * a / 2 - tmp) * 2;
+        double dotted = a * a - PI * a * a / 4 - 2 * checkered;
+        double striped = a * a - 4 * checkered - 4 * dotted;
+
+        cout << fixed << setprecision(3) << striped << " " << dotted * 4 << " " << checkered * 4 << endl;
+    }
+
+    return 0;
+}