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Bug fixes and improvements (#1298)
* Fix is_empty() implementation in the stack and queue chapter * Update en/CONTRIBUTING.md * Remove "剩余" from the state definition of knapsack problem * Sync zh and zh-hant versions * Update the stylesheets of code tabs * Fix quick_sort.rb * Fix TS code * Update chapter_paperbook * Upload the manuscript of 0.1 section * Fix binary_tree_dfs.rb * Bug fixes * Update README * Update README * Update README * Update README.md * Update README * Sync zh and zh-hant versions * Bug fixes
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=begin
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File: quick_sort.rb
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Created Time: 2024-04-01
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Author: Cy (3739004@gmail.com), Xuan Khoa Tu Nguyen (ngxktuzkai2000@gmail.com)
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=end
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### 快速排序類別 ###
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class QuickSort
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class << self
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### 哨兵劃分 ###
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def partition(nums, left, right)
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# 以 nums[left] 為基準數
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i, j = left, right
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while i < j
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while i < j && nums[j] >= nums[left]
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j -= 1 # 從右向左找首個小於基準數的元素
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end
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while i < j && nums[i] <= nums[left]
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i += 1 # 從左向右找首個大於基準數的元素
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end
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# 元素交換
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nums[i], nums[j] = nums[j], nums[i]
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end
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# 將基準數交換至兩子陣列的分界線
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nums[i], nums[left] = nums[left], nums[i]
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i # 返回基準數的索引
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end
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### 快速排序類別 ###
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def quick_sort(nums, left, right)
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# 子陣列長度不為 1 時遞迴
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if left < right
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# 哨兵劃分
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pivot = partition(nums, left, right)
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# 遞迴左子陣列、右子陣列
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quick_sort(nums, left, pivot - 1)
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quick_sort(nums, pivot + 1, right)
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end
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nums
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end
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end
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end
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### 快速排序類別(中位數最佳化)###
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class QuickSortMedian
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class << self
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### 選取三個候選元素的中位數 ###
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def median_three(nums, left, mid, right)
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# 選取三個候選元素的中位數
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_l, _m, _r = nums[left], nums[mid], nums[right]
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# m 在 l 和 r 之間
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return mid if (_l <= _m && _m <= _r) || (_r <= _m && _m <= _l)
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# l 在 m 和 r 之間
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return left if (_m <= _l && _l <= _r) || (_r <= _l && _l <= _m)
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return right
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end
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### 哨兵劃分(三數取中值)###
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def partition(nums, left, right)
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### 以 nums[left] 為基準數
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med = median_three(nums, left, (left + right) / 2, right)
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# 將中位數交換至陣列最左斷
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nums[left], nums[med] = nums[med], nums[left]
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i, j = left, right
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while i < j
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while i < j && nums[j] >= nums[left]
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j -= 1 # 從右向左找首個小於基準數的元素
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end
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while i < j && nums[i] <= nums[left]
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i += 1 # 從左向右找首個大於基準數的元素
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end
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# 元素交換
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nums[i], nums[j] = nums[j], nums[i]
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end
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# 將基準數交換至兩子陣列的分界線
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nums[i], nums[left] = nums[left], nums[i]
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i # 返回基準數的索引
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end
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### 快速排序 ###
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def quick_sort(nums, left, right)
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# 子陣列長度不為 1 時遞迴
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if left < right
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# 哨兵劃分
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pivot = partition(nums, left, right)
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# 遞迴左子陣列、右子陣列
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quick_sort(nums, left, pivot - 1)
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quick_sort(nums, pivot + 1, right)
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end
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nums
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end
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end
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end
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### 快速排序類別(尾遞迴最佳化)###
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class QuickSortTailCall
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class << self
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### 哨兵劃分 ###
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def partition(nums, left, right)
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# 以 nums[left]為基準數
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i = left
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j = right
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while i < j
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while i < j && nums[j] >= nums[left]
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j -= 1 # 從右向左找首個小於基準數的元素
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end
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while i < j && nums[i] <= nums[left]
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i += 1 # 從左向右找首個大於基準數的元素
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end
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# 元素交換
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nums[i], nums[j] = nums[j], nums[i]
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end
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# 將基準數交換至兩子陣列的分界線
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nums[i], nums[left] = nums[left], nums[i]
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i # 返回基準數的索引
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end
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### 快速排序(尾遞迴最佳化)
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def quick_sort(nums, left, right)
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# 子陣列長度不為 1 時遞迴
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while left < right
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# 哨兵劃分
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pivot = partition(nums, left, right)
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# 對兩個子陣列中較短的那個執行快速排序
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if pivot - left < right - pivot
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quick_sort(nums, left, pivot - 1)
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left = pivot + 1 # 剩餘未排序區間為 [pivot + 1, right]
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else
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quick_sort(nums, pivot + 1, right)
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right = pivot - 1 # 剩餘未排序區間為 [left, pivot - 1]
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end
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end
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end
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end
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end
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### Driver Code ###
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if __FILE__ == $0
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# 快速排序
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nums = [2, 4, 1, 0, 3, 5]
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QuickSort.quick_sort(nums, 0, nums.length - 1)
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puts "快速排序完成後 nums = #{nums}"
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# 快速排序(中位基準數最佳化)
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nums1 = [2, 4, 1, 0, 3, 5]
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QuickSortMedian.quick_sort(nums1, 0, nums1.length - 1)
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puts "快速排序(中位基準數最佳化)完成後 nums1 = #{nums1}"
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# 快速排序(尾遞迴最佳化)
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nums2 = [2, 4, 1, 0, 3, 5]
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QuickSortTailCall.quick_sort(nums2, 0, nums2.length - 1)
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puts "快速排序(尾遞迴最佳化)完成後 nums2 = #{nums2}"
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end
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