From 79ade249027f6872ae3546b0d2afca4ea2484145 Mon Sep 17 00:00:00 2001
From: krahets <krahets@163.com>
Date: Sat, 22 Jul 2023 03:58:19 +0800
Subject: [PATCH] build

---
 chapter_appendix/index.md                     |  5 +++
 chapter_greedy/fractional_knapsack_problem.md | 37 ++++++++++++++++++-
 chapter_greedy/greedy_algorithm.md            | 19 +++++++++-
 chapter_greedy/max_capacity_problem.md        | 21 ++++++++++-
 chapter_greedy/max_product_cutting_problem.md | 21 ++++++++++-
 5 files changed, 98 insertions(+), 5 deletions(-)

diff --git a/chapter_appendix/index.md b/chapter_appendix/index.md
index 057aa055e..32a30e4ca 100644
--- a/chapter_appendix/index.md
+++ b/chapter_appendix/index.md
@@ -5,6 +5,11 @@ icon: material/help-circle-outline
 
 # 16. &nbsp; 附录
 
+<div class="center-table" markdown>
+
+![附录](../assets/covers/chapter_appendix.jpg){ width="70%" }
+
+</div>
 
 ## 本章内容
 
diff --git a/chapter_greedy/fractional_knapsack_problem.md b/chapter_greedy/fractional_knapsack_problem.md
index 30da64082..d9a297477 100644
--- a/chapter_greedy/fractional_knapsack_problem.md
+++ b/chapter_greedy/fractional_knapsack_problem.md
@@ -189,9 +189,42 @@ status: new
 === "C#"
 
     ```csharp title="fractional_knapsack.cs"
-    [class]{Item}-[func]{}
+    /* 物品 */
+    class Item {
+        public int w; // 物品重量
+        public int v; // 物品价值
 
-    [class]{fractional_knapsack}-[func]{fractionalKnapsack}
+        public Item(int w, int v) {
+            this.w = w;
+            this.v = v;
+        }
+    }
+
+    /* 分数背包：贪心 */
+    double fractionalKnapsack(int[] wgt, int[] val, int cap) {
+        // 创建物品列表，包含两个属性：重量、价值
+        Item[] items = new Item[wgt.Length];
+        for (int i = 0; i < wgt.Length; i++) {
+            items[i] = new Item(wgt[i], val[i]);
+        }
+        // 按照单位价值 item.v / item.w 从高到低进行排序
+        Array.Sort(items, (x, y) => (y.v / y.w).CompareTo(x.v / x.w));
+        // 循环贪心选择
+        double res = 0;
+        foreach (Item item in items) {
+            if (item.w <= cap) {
+                // 若剩余容量充足，则将当前物品整个装进背包
+                res += item.v;
+                cap -= item.w;
+            } else {
+                // 若剩余容量不足，则将当前物品的一部分装进背包
+                res += (double)item.v / item.w * cap;
+                // 已无剩余容量，因此跳出循环
+                break;
+            }
+        }
+        return res;
+    }
     ```
 
 === "Swift"
diff --git a/chapter_greedy/greedy_algorithm.md b/chapter_greedy/greedy_algorithm.md
index 8d01193e2..fe133d299 100644
--- a/chapter_greedy/greedy_algorithm.md
+++ b/chapter_greedy/greedy_algorithm.md
@@ -119,7 +119,24 @@ status: new
 === "C#"
 
     ```csharp title="coin_change_greedy.cs"
-    [class]{coin_change_greedy}-[func]{coinChangeGreedy}
+    /* 零钱兑换：贪心 */
+    int coinChangeGreedy(int[] coins, int amt) {
+        // 假设 coins 列表有序
+        int i = coins.Length - 1;
+        int count = 0;
+        // 循环进行贪心选择，直到无剩余金额
+        while (amt > 0) {
+            // 找到小于且最接近剩余金额的硬币
+            while (coins[i] > amt) {
+                i--;
+            }
+            // 选择 coins[i]
+            amt -= coins[i];
+            count++;
+        }
+        // 若未找到可行方案，则返回 -1
+        return amt == 0 ? count : -1;
+    }
     ```
 
 === "Swift"
diff --git a/chapter_greedy/max_capacity_problem.md b/chapter_greedy/max_capacity_problem.md
index c67d731d4..de6909034 100644
--- a/chapter_greedy/max_capacity_problem.md
+++ b/chapter_greedy/max_capacity_problem.md
@@ -185,7 +185,26 @@ $$
 === "C#"
 
     ```csharp title="max_capacity.cs"
-    [class]{max_capacity}-[func]{maxCapacity}
+    /* 最大容量：贪心 */
+    int maxCapacity(int[] ht) {
+        // 初始化 i, j 分列数组两端
+        int i = 0, j = ht.Length - 1;
+        // 初始最大容量为 0
+        int res = 0;
+        // 循环贪心选择，直至两板相遇
+        while (i < j) {
+            // 更新最大容量
+            int cap = Math.Min(ht[i], ht[j]) * (j - i);
+            res = Math.Max(res, cap);
+            // 向内移动短板
+            if (ht[i] < ht[j]) {
+                i++;
+            } else {
+                j--;
+            }
+        }
+        return res;
+    }
     ```
 
 === "Swift"
diff --git a/chapter_greedy/max_product_cutting_problem.md b/chapter_greedy/max_product_cutting_problem.md
index 065c476e1..79c7cbb84 100644
--- a/chapter_greedy/max_product_cutting_problem.md
+++ b/chapter_greedy/max_product_cutting_problem.md
@@ -171,7 +171,26 @@ $$
 === "C#"
 
     ```csharp title="max_product_cutting.cs"
-    [class]{max_product_cutting}-[func]{maxProductCutting}
+    /* 最大切分乘积：贪心 */
+    int maxProductCutting(int n) {
+        // 当 n <= 3 时，必须切分出一个 1
+        if (n <= 3) {
+            return 1 * (n - 1);
+        }
+        // 贪心地切分出 3 ，a 为 3 的个数，b 为余数
+        int a = n / 3;
+        int b = n % 3;
+        if (b == 1) {
+            // 当余数为 1 时，将一对 1 * 3 转化为 2 * 2
+            return (int)Math.Pow(3, a - 1) * 2 * 2;
+        }
+        if (b == 2) {
+            // 当余数为 2 时，不做处理
+            return (int)Math.Pow(3, a) * 2;
+        }
+        // 当余数为 0 时，不做处理
+        return (int)Math.Pow(3, a);
+    }
     ```
 
 === "Swift"