From 1d4b25c7de15859211616990322cb35b888c4205 Mon Sep 17 00:00:00 2001
From: Xu Shaohua <shaohua@biofan.org>
Date: Thu, 19 Sep 2024 12:24:04 +0800
Subject: [PATCH] e100: Add cpp impl of share candy

---
 src/od/2024e100/share-candy/.gitignore   |  1 +
 src/od/2024e100/share-candy/Makefile     |  3 ++
 src/od/2024e100/share-candy/index.md     |  6 ++++
 src/od/2024e100/share-candy/solution.cpp | 46 ++++++++++++++++++++++++
 4 files changed, 56 insertions(+)
 create mode 100644 src/od/2024e100/share-candy/.gitignore
 create mode 100644 src/od/2024e100/share-candy/Makefile
 create mode 100644 src/od/2024e100/share-candy/solution.cpp

diff --git a/src/od/2024e100/share-candy/.gitignore b/src/od/2024e100/share-candy/.gitignore
new file mode 100644
index 00000000..a005e384
--- /dev/null
+++ b/src/od/2024e100/share-candy/.gitignore
@@ -0,0 +1 @@
+/solution
diff --git a/src/od/2024e100/share-candy/Makefile b/src/od/2024e100/share-candy/Makefile
new file mode 100644
index 00000000..fda8590d
--- /dev/null
+++ b/src/od/2024e100/share-candy/Makefile
@@ -0,0 +1,3 @@
+
+solution: solution.cpp
+	g++ solution.cpp -o solution
diff --git a/src/od/2024e100/share-candy/index.md b/src/od/2024e100/share-candy/index.md
index cbc678b5..cecdff53 100644
--- a/src/od/2024e100/share-candy/index.md
+++ b/src/od/2024e100/share-candy/index.md
@@ -58,6 +58,12 @@
 {{#include solution.py:6:}}
 ```
 
+### C++
+
+```cpp
+{{#include solution.cpp:5:}}
+```
+
 ### Rust
 
 ```rust
diff --git a/src/od/2024e100/share-candy/solution.cpp b/src/od/2024e100/share-candy/solution.cpp
new file mode 100644
index 00000000..ec12f169
--- /dev/null
+++ b/src/od/2024e100/share-candy/solution.cpp
@@ -0,0 +1,46 @@
+// Copyright (c) 2024 Xu Shaohua <shaohua@biofan.org>. All rights reserved.
+// Use of this source is governed by General Public License that can be found
+// in the LICENSE file.
+
+#include <iostream>
+#include <unordered_map>
+
+// 缓存 + 递归
+int get_minimum_times(int num, std::unordered_map<int, int>& cache) {
+  const auto iter = cache.find(num);
+  if (iter != cache.end()) {
+    return iter->second;
+  }
+
+  if (num % 2 == 0) {
+    // 如果是偶数个
+    // 平均分一次
+    const int times = 1 + get_minimum_times(num / 2, cache);
+    cache[num] = times;
+    return times;
+  } else {
+    // 如果是奇数个, 有两种方式:
+    // 取一个
+    const int times1 = 1 + get_minimum_times(num + 1, cache);
+    // 放一个
+    const int times2 = 1 + get_minimum_times(num - 1, cache);
+            
+    // 求它们的最小值
+    const int min_times = std::min(times1, times2);
+    cache[num] = min_times;
+    return min_times;
+  }
+}
+
+int main() {
+  std::unordered_map<int, int> cache;
+  cache[1] = 0;
+
+  int num_candies = 0;
+  std::cin >> num_candies;
+
+  const int times = get_minimum_times(num_candies, cache);
+  std::cout << times << std::endl;
+
+  return 0;
+}