Feature/chapter dynamic programming swift (#608)

* feat: add Swift codes for intro_to_dynamic_programming article * feat: add Swift codes for dp_problem_features article * feat: add Swift codes for dp_solution_pipeline article * feat: add Swift codes for knapsack_problem article * feat: add Swift codes for unbounded_knapsack_problem article * feat: add Swift codes for edit_distance_problem article
2026-08-20 07:21:02 +00:00 · 2023-07-18 12:49:03 +08:00
parent 34985bdf2b
commit 9ea8a73059
13 changed files with 855 additions and 0 deletions
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+/**
+ * File: climbing_stairs_dp.swift
+ * Created Time: 2023-07-15
+ * Author: nuomi1 (nuomi1@qq.com)
+ */
+
+/* 爬楼梯：动态规划 */
+func climbingStairsDP(n: Int) -> Int {
+    if n == 1 || n == 2 {
+        return n
+    }
+    // 初始化 dp 表，用于存储子问题的解
+    var dp = Array(repeating: 0, count: 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 i in stride(from: 3, through: n, by: 1) {
+        dp[i] = dp[i - 1] + dp[i - 2]
+    }
+    return dp[n]
+}
+
+/* 爬楼梯：状态压缩后的动态规划 */
+func climbingStairsDPComp(n: Int) -> Int {
+    if n == 1 || n == 2 {
+        return n
+    }
+    var a = 1
+    var b = 2
+    for _ in stride(from: 3, through: n, by: 1) {
+        (a, b) = (b, a + b)
+    }
+    return b
+}
+
+@main
+enum ClimbingStairsDP {
+    /* Driver Code */
+    static func main() {
+        let n = 9
+
+        var res = climbingStairsDP(n: n)
+        print("爬 \(n) 阶楼梯共有 \(res) 种方案")
+
+        res = climbingStairsDPComp(n: n)
+        print("爬 \(n) 阶楼梯共有 \(res) 种方案")
+    }
+}