feat: Add Dart codes for chapter_dynamic_programming and chapter_greedy (#683)

* feat: Add Dart codes for chapter_dynamic_programming * feat: Add Dart codes for chapter_greedy
2026-08-20 23:41:00 +00:00 · 2023-08-13 19:29:54 +08:00
parent 4325974af1
commit 10c397b172
16 changed files with 949 additions and 0 deletions
@@ -0,0 +1,39 @@
+/**
+ * File: climbing_stairs_backtrack.dart
+ * Created Time: 2023-08-11
+ * Author: liuyuxin (gvenusleo@gmail.com)
+ */
+
+/* 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
+  for (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
+  }
+}
+
+/* 爬楼梯：回溯 */
+int climbingStairsBacktrack(int n) {
+  List<int> choices = [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 = [];
+  res.add(0); // 使用 res[0] 记录方案数量
+  backtrack(choices, state, n, res);
+  return res[0];
+}
+
+/* Driver Code */
+void main() {
+  int n = 9;
+
+  int res = climbingStairsBacktrack(n);
+  print("爬 $n 阶楼梯共有 $res 种方案");
+}