Add chuanzhi-cup codes.

1 files changed, 38 insertions, 0 deletions

diff --git a/chuanzhi-cup/practice-contest/3.cpp b/chuanzhi-cup/practice-contest/3.cpp
new file mode 100644
index 0000000..1f79723
--- /dev/null
+++ b/chuanzhi-cup/practice-contest/3.cpp
@@ -0,0 +1,38 @@
+#include <cmath>

+#include <iomanip>

+#include <iostream>

+#include <regex>

+#include <string>

+

+int main() {

+  std::string input;

+  std::getline(std::cin, input);

+

+  std::regex reg(R"aaa((\d+)([GMK]?B)=\?([GMK]?B))aaa");

+  std::smatch match;

+  std::regex_match(input, match, reg);

+

+  std::string original_number_str = match[1].str();

+  std::string original_unit = match[2].str();

+  std::string target_unit = match[3].str();

+

+  double original_number = std::stod(original_number_str);

+

+  auto to_ratio = [](const std::string s) -> double {

+    if (s.size() == 1)

+      return 1;

+    if (s[0] == 'G')

+      return std::pow(2, 30);

+    if (s[0] == 'M')

+      return std::pow(2, 20);

+    return std::pow(2, 10);

+  };

+

+  double original_ratio = to_ratio(original_unit);

+  double target_ratio = to_ratio(target_unit);

+

+  std::cout << std::fixed << std::setprecision(6)

+            << (original_number * original_ratio / target_ratio);

+

+  return 0;

+}