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https://github.com/krahets/hello-algo.git
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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
36 lines
829 B
Go
36 lines
829 B
Go
// File: climbing_stairs_backtrack.go
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// Created Time: 2023-07-18
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// Author: Reanon (793584285@qq.com)
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package chapter_dynamic_programming
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/* 回溯 */
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func backtrack(choices []int, state, n int, res []int) {
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// 当爬到第 n 阶时，方案数量加 1
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if state == n {
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res[0] = res[0] + 1
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}
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// 遍历所有选择
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for _, choice := range choices {
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// 剪枝：不允许越过第 n 阶
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if state+choice > n {
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continue
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}
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// 尝试：做出选择，更新状态
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backtrack(choices, state+choice, n, res)
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// 回退
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}
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}
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/* 爬楼梯：回溯 */
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func climbingStairsBacktrack(n int) int {
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// 可选择向上爬 1 阶或 2 阶
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choices := []int{1, 2}
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// 从第 0 阶开始爬
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state := 0
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res := make([]int, 1)
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// 使用 res[0] 记录方案数量
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res[0] = 0
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backtrack(choices, state, n, res)
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return res[0]
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}
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