1995 - 暗影岛的歌声

77471

bjtu/1995/1995.cpp

@@ -0,0 +1,31 @@
+#include <iostream>
+#include <iomanip>
+#include <string>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const double d[] = {0, 261.6, 293.6, 329.6, 349.2, 392.0, 440.0, 493.8};
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    std::string s;
+    double ans = 0;
+
+    cin >> s;
+
+    for (int i = 1; i < s.size(); i++) {
+        if (s[i] == '-') s[i] = s[i - 1];
+    }
+
+    for (char c : s) {
+        ans += d[c - '0'];
+    }
+
+    cout << std::fixed << std::setprecision(6) << ans / s.size() << endl;
+
+    return 0;
+}