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

codes/python/chapter_stack_and_queue/array_stack.py

@@ -18,7 +18,7 @@ class ArrayStack:
 
     def is_empty(self) -> bool:
         """判断栈是否为空"""
-        return self._stack == []
+        return self.size() == 0
 
     def push(self, item: int):
         """入栈"""

codes/python/chapter_stack_and_queue/linkedlist_deque.py

@@ -30,7 +30,7 @@ class LinkedListDeque:
 
     def is_empty(self) -> bool:
         """判断双向队列是否为空"""
-        return self.size() == 0
+        return self._size == 0
 
     def push(self, num: int, is_front: bool):
         """入队操作"""

codes/python/chapter_stack_and_queue/linkedlist_queue.py

@@ -26,7 +26,7 @@ class LinkedListQueue:
 
     def is_empty(self) -> bool:
         """判断队列是否为空"""
-        return not self._front
+        return self._size == 0
 
     def push(self, num: int):
         """入队"""

codes/python/chapter_stack_and_queue/linkedlist_stack.py

@@ -25,7 +25,7 @@ class LinkedListStack:
 
     def is_empty(self) -> bool:
         """判断栈是否为空"""
-        return not self._peek
+        return self._size == 0
 
     def push(self, val: int):
         """入栈"""

codes/ruby/chapter_sorting/quick_sort.rb

@@ -136,16 +136,17 @@ class QuickSortTailCall
 end
 
 ### Driver Code ###
-
 if __FILE__ == $0
   # 快速排序
   nums = [2, 4, 1, 0, 3, 5]
   QuickSort.quick_sort(nums, 0, nums.length - 1)
   puts "快速排序完成后 nums = #{nums}"
+
   # 快速排序（中位基准数优化）
   nums1 = [2, 4, 1, 0, 3, 5]
   QuickSortMedian.quick_sort(nums1, 0, nums1.length - 1)
   puts "快速排序（中位基准数优化）完成后 nums1 = #{nums1}"
+
   # 快速排序（尾递归优化）
   nums2 = [2, 4, 1, 0, 3, 5]
   QuickSortTailCall.quick_sort(nums2, 0, nums2.length - 1)

codes/ruby/chapter_tree/binary_tree_dfs.rb

@@ -8,13 +8,13 @@ require_relative '../utils/tree_node'
 require_relative '../utils/print_util'
 
 ### 前序遍历 ###
-def pre_oder(root)
+def pre_order(root)
   return if root.nil?
 
   # 访问优先级：根节点 -> 左子树 -> 右子树
   $res << root.val
-  pre_oder(root.left)
-  pre_oder(root.right)
+  pre_order(root.left)
+  pre_order(root.right)
 end
 
 ### 中序遍历 ###
@@ -47,7 +47,7 @@ if __FILE__ == $0
 
   # 前序遍历
   $res = []
-  pre_oder(root)
+  pre_order(root)
   puts "\n前序遍历的节点打印序列 = #{$res}"
 
   # 中序遍历

codes/typescript/chapter_backtracking/subset_sum_i.ts

@@ -51,4 +51,4 @@ const res = subsetSumI(nums, target);
 console.log(`输入数组 nums = ${JSON.stringify(nums)}, target = ${target}`);
 console.log(`所有和等于 ${target} 的子集 res = ${JSON.stringify(res)}`);
 
-export { };
+export {};

codes/typescript/chapter_backtracking/subset_sum_ii.ts

@@ -56,4 +56,4 @@ const res = subsetSumII(nums, target);
 console.log(`输入数组 nums = ${JSON.stringify(nums)}, target = ${target}`);
 console.log(`所有和等于 ${target} 的子集 res = ${JSON.stringify(res)}`);
 
-export { };
+export {};

codes/typescript/chapter_computational_complexity/recursion.ts

@@ -67,4 +67,4 @@ console.log(`尾递归函数的求和结果 res = ${res}`);
 res = fib(n);
 console.log(`斐波那契数列的第 ${n} 项为 ${res}`);
 
-export { };
+export {};