mirror of
https://github.com/krahets/hello-algo.git
synced 2025-11-01 03:24:24 +08:00
e720aa2d24
* Sync recent changes to the revised Word. * Revised the preface chapter * Revised the introduction chapter * Revised the computation complexity chapter * Revised the chapter data structure * Revised the chapter array and linked list * Revised the chapter stack and queue * Revised the chapter hashing * Revised the chapter tree * Revised the chapter heap * Revised the chapter graph * Revised the chapter searching * Reivised the sorting chapter * Revised the divide and conquer chapter * Revised the chapter backtacking * Revised the DP chapter * Revised the greedy chapter * Revised the appendix chapter * Revised the preface chapter doubly * Revised the figures
42 lines
1.2 KiB
C#
42 lines
1.2 KiB
C#
/**
|
|
* File: climbing_stairs_backtrack.cs
|
|
* Created Time: 2023-06-30
|
|
* Author: hpstory (hpstory1024@163.com)
|
|
*/
|
|
|
|
namespace hello_algo.chapter_dynamic_programming;
|
|
|
|
public class climbing_stairs_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)
|
|
continue;
|
|
// 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 阶或 2 阶
|
|
int state = 0; // 从第 0 阶开始爬
|
|
List<int> res = [0]; // 使用 res[0] 记录方案数量
|
|
Backtrack(choices, state, n, res);
|
|
return res[0];
|
|
}
|
|
|
|
[Test]
|
|
public void Test() {
|
|
int n = 9;
|
|
int res = ClimbingStairsBacktrack(n);
|
|
Console.WriteLine($"爬 {n} 阶楼梯共有 {res} 种方案");
|
|
}
|
|
}
|