build

chapter_dynamic_programming/dp_problem_features.md

@@ -123,7 +123,22 @@ $$
 === "C#"
 
     ```csharp title="min_cost_climbing_stairs_dp.cs"
-    [class]{min_cost_climbing_stairs_dp}-[func]{minCostClimbingStairsDP}
+    /* 爬楼梯最小代价：动态规划 */
+    int minCostClimbingStairsDP(int[] cost) {
+        int n = cost.Length - 1;
+        if (n == 1 || n == 2)
+            return cost[n];
+        // 初始化 dp 列表，用于存储子问题的解
+        int[] dp = new int[n + 1];
+        // 初始状态：预设最小子问题的解
+        dp[1] = cost[1];
+        dp[2] = cost[2];
+        // 状态转移：从较小子问题逐步求解较大子问题
+        for (int i = 3; i <= n; i++) {
+            dp[i] = Math.Min(dp[i - 1], dp[i - 2]) + cost[i];
+        }
+        return dp[n];
+    }
     ```
 
 === "Swift"
@@ -227,7 +242,19 @@ $$
 === "C#"
 
     ```csharp title="min_cost_climbing_stairs_dp.cs"
-    [class]{min_cost_climbing_stairs_dp}-[func]{minCostClimbingStairsDPComp}
+    /* 爬楼梯最小代价：状态压缩后的动态规划 */
+    int minCostClimbingStairsDPComp(int[] cost) {
+        int n = cost.Length - 1;
+        if (n == 1 || n == 2)
+            return cost[n];
+        int a = cost[1], b = cost[2];
+        for (int i = 3; i <= n; i++) {
+            int tmp = b;
+            b = Math.Min(a, tmp) + cost[i];
+            a = tmp;
+        }
+        return b;
+    }
     ```
 
 === "Swift"
@@ -384,7 +411,25 @@ $$
 === "C#"
 
     ```csharp title="climbing_stairs_constraint_dp.cs"
-    [class]{climbing_stairs_constraint_dp}-[func]{climbingStairsConstraintDP}
+    /* 带约束爬楼梯：动态规划 */
+    int climbingStairsConstraintDP(int n) {
+        if (n == 1 || n == 2) {
+            return n;
+        }
+        // 初始化 dp 列表，用于存储子问题的解
+        int[,] dp = new int[n + 1, 3];
+        // 初始状态：预设最小子问题的解
+        dp[1, 1] = 1;
+        dp[1, 2] = 0;
+        dp[2, 1] = 0;
+        dp[2, 2] = 1;
+        // 状态转移：从较小子问题逐步求解较大子问题
+        for (int i = 3; i <= n; i++) {
+            dp[i, 1] = dp[i - 1, 2];
+            dp[i, 2] = dp[i - 2, 1] + dp[i - 2, 2];
+        }
+        return dp[n, 1] + dp[n, 2];
+    }
     ```
 
 === "Swift"

chapter_dynamic_programming/intro_to_dynamic_programming.md

@@ -140,9 +140,30 @@ comments: true
 === "C#"
 
     ```csharp title="climbing_stairs_backtrack.cs"
-    [class]{climbing_stairs_backtrack}-[func]{backtrack}
+    /* 回溯 */
+    void backtrack(List<int> choices, int state, int n, List<int> res) {
+        // 当爬到第 n 阶时，方案数量加 1
+        if (state == n)
+            res[0]++;
+        // 遍历所有选择
+        foreach (int choice in choices) {
+            // 剪枝：不允许越过第 n 阶
+            if (state + choice > n)
+                break;
+            // 尝试：做出选择，更新状态
+            backtrack(choices, state + choice, n, res);
+            // 回退
+        }
+    }
 
-    [class]{climbing_stairs_backtrack}-[func]{climbingStairsBacktrack}
+    /* 爬楼梯：回溯 */
+    int climbingStairsBacktrack(int n) {
+        List<int> choices = new List<int> { 1, 2 }; // 可选择向上爬 1 或 2 阶
+        int state = 0; // 从第 0 阶开始爬
+        List<int> res = new List<int> { 0 }; // 使用 res[0] 记录方案数量
+        backtrack(choices, state, n, res);
+        return res[0];
+    }
     ```
 
 === "Swift"
@@ -285,9 +306,20 @@ $$
 === "C#"
 
     ```csharp title="climbing_stairs_dfs.cs"
-    [class]{climbing_stairs_dfs}-[func]{dfs}
+    /* 搜索 */
+    int dfs(int i) {
+        // 已知 dp[1] 和 dp[2] ，返回之
+        if (i == 1 || i == 2)
+            return i;
+        // dp[i] = dp[i-1] + dp[i-2]
+        int count = dfs(i - 1) + dfs(i - 2);
+        return count;
+    }
 
-    [class]{climbing_stairs_dfs}-[func]{climbingStairsDFS}
+    /* 爬楼梯：搜索 */
+    int climbingStairsDFS(int n) {
+        return dfs(n);
+    }
     ```
 
 === "Swift"
@@ -441,9 +473,28 @@ $$
 === "C#"
 
     ```csharp title="climbing_stairs_dfs_mem.cs"
-    [class]{climbing_stairs_dfs_mem}-[func]{dfs}
+    /* 记忆化搜索 */
+    int dfs(int i, int[] mem) {
+        // 已知 dp[1] 和 dp[2] ，返回之
+        if (i == 1 || i == 2)
+            return i;
+        // 若存在记录 dp[i] ，则直接返回之
+        if (mem[i] != -1)
+            return mem[i];
+        // dp[i] = dp[i-1] + dp[i-2]
+        int count = dfs(i - 1, mem) + dfs(i - 2, mem);
+        // 记录 dp[i]
+        mem[i] = count;
+        return count;
+    }
 
-    [class]{climbing_stairs_dfs_mem}-[func]{climbingStairsDFSMem}
+    /* 爬楼梯：记忆化搜索 */
+    int climbingStairsDFSMem(int n) {
+        // mem[i] 记录爬到第 i 阶的方案总数，-1 代表无记录
+        int[] mem = new int[n + 1];
+        Array.Fill(mem, -1);
+        return dfs(n, mem);
+    }
     ```
 
 === "Swift"
@@ -568,7 +619,21 @@ $$
 === "C#"
 
     ```csharp title="climbing_stairs_dp.cs"
-    [class]{climbing_stairs_dp}-[func]{climbingStairsDP}
+    /* 爬楼梯：动态规划 */
+    int climbingStairsDP(int n) {
+        if (n == 1 || n == 2)
+            return n;
+        // 初始化 dp 列表，用于存储子问题的解
+        int[] dp = new int[n + 1];
+        // 初始状态：预设最小子问题的解
+        dp[1] = 1;
+        dp[2] = 2;
+        // 状态转移：从较小子问题逐步求解较大子问题
+        for (int i = 3; i <= n; i++) {
+            dp[i] = dp[i - 1] + dp[i - 2];
+        }
+        return dp[n];
+    }
     ```
 
 === "Swift"
@@ -675,7 +740,18 @@ $$
 === "C#"
 
     ```csharp title="climbing_stairs_dp.cs"
-    [class]{climbing_stairs_dp}-[func]{climbingStairsDPComp}
+    /* 爬楼梯：状态压缩后的动态规划 */
+    int climbingStairsDPComp(int n) {
+        if (n == 1 || n == 2)
+            return n;
+        int a = 1, b = 2;
+        for (int i = 3; i <= n; i++) {
+            int tmp = b;
+            b = a + b;
+            a = tmp;
+        }
+        return b;
+    }
     ```
 
 === "Swift"

chapter_hashing/hash_algorithm.md

@@ -309,13 +309,53 @@ index = hash(key) % capacity
 === "Swift"
 
     ```swift title="simple_hash.swift"
-    [class]{}-[func]{addHash}
+    /* 加法哈希 */
+    func addHash(key: String) -> Int {
+        var hash = 0
+        let MODULUS = 1_000_000_007
+        for c in key {
+            for scalar in c.unicodeScalars {
+                hash = (hash + Int(scalar.value)) % MODULUS
+            }
+        }
+        return hash
+    }
 
-    [class]{}-[func]{mulHash}
+    /* 乘法哈希 */
+    func mulHash(key: String) -> Int {
+        var hash = 0
+        let MODULUS = 1_000_000_007
+        for c in key {
+            for scalar in c.unicodeScalars {
+                hash = (31 * hash + Int(scalar.value)) % MODULUS
+            }
+        }
+        return hash
+    }
 
-    [class]{}-[func]{xorHash}
+    /* 异或哈希 */
+    func xorHash(key: String) -> Int {
+        var hash = 0
+        let MODULUS = 1_000_000_007
+        for c in key {
+            for scalar in c.unicodeScalars {
+                hash ^= Int(scalar.value)
+            }
+        }
+        return hash & MODULUS
+    }
 
-    [class]{}-[func]{rotHash}
+    /* 旋转哈希 */
+    func rotHash(key: String) -> Int {
+        var hash = 0
+        let MODULUS = 1_000_000_007
+        for c in key {
+            for scalar in c.unicodeScalars {
+                hash = ((hash << 4) ^ (hash >> 28) ^ Int(scalar.value)) % MODULUS
+            }
+        }
+        return hash
+    }
     ```
 
 === "Zig"
@@ -533,7 +573,29 @@ $$
 === "Swift"
 
     ```swift title="built_in_hash.swift"
+    let num = 3
+    let hashNum = num.hashValue
+    // 整数 3 的哈希值为 9047044699613009734
 
+    let bol = true
+    let hashBol = bol.hashValue
+    // 布尔量 true 的哈希值为 -4431640247352757451
+
+    let dec = 3.14159
+    let hashDec = dec.hashValue
+    // 小数 3.14159 的哈希值为 -2465384235396674631
+
+    let str = "Hello 算法"
+    let hashStr = str.hashValue
+    // 字符串 Hello 算法 的哈希值为 -7850626797806988787
+
+    let arr = [AnyHashable(12836), AnyHashable("小哈")]
+    let hashTup = arr.hashValue
+    // 数组 [AnyHashable(12836), AnyHashable("小哈")] 的哈希值为 -2308633508154532996
+
+    let obj = ListNode(x: 0)
+    let hashObj = obj.hashValue
+    // 节点对象 utils.ListNode 的哈希值为 -2434780518035996159
     ```
 
 === "Zig"

index.md

@@ -113,6 +113,7 @@ hide:
         <tbody>
             <td align="center"><a href="https://github.com/Gonglja"><img src="https://avatars.githubusercontent.com/u/39959756?v=4" width="50px;" alt="Gonglja"/><br /><sub><b>Gonglja</b></sub></a><br /><sub>C / C++</sub></td>
             <td align="center"><a href="https://github.com/gvenusleo"><img src="https://avatars.githubusercontent.com/u/79075347?v=4" width="50px;" alt="gvenusleo"/><br /><sub><b>gvenusleo</b></sub></a><br /><sub>Dart</sub></td>
+            <td align="center"><a href="https://github.com/hpstory"><img src="https://avatars.githubusercontent.com/u/33348162?v=4" width="50px;" alt="hpstory"/><br /><sub><b>hpstory</b></sub></a><br /><sub>C#</sub></td>
             <td align="center"><a href="https://github.com/justin-tse"><img src="https://avatars.githubusercontent.com/u/24556310?v=4" width="50px;" alt="justin-tse"/><br /><sub><b>justin-tse</b></sub></a><br /><sub>JS / TS</sub></td>
             <td align="center"><a href="https://github.com/krahets"><img src="https://avatars.githubusercontent.com/u/26993056?v=4" width="50px;" alt="krahets"/><br /><sub><b>krahets</b></sub></a><br /><sub>Java / Python</sub></td>
             <td align="center"><a href="https://github.com/nuomi1"><img src="https://avatars.githubusercontent.com/u/3739017?v=4" width="50px;" alt="nuomi1"/><br /><sub><b>nuomi1</b></sub></a><br /><sub>Swift</sub></td>