delete week03, and refactor according to tags

Week03/22.py → Backtracking/22_GenerateParentheses.py

@@ -44,3 +44,10 @@ def generate_child_tree(self, node, n, solution):
         right_child = [None, None, node[2], node[3] + 1, node[4] + ")"]
         node[1] = right_child
         self.generate_child_tree(right_child, n, solution)
+
+"""
+0
+1
+3
+5
+"""

Week03/23.py → Heap/23_MergeKSortedLists.py

@@ -43,3 +43,8 @@ def mergeKLists(self, lists):
                 heapq.heappush(heap_record, (next_node.val, next_node))
 
         return head.next
+
+"""
+[]
+[[1,4,5,6,9], [2,3,4,5,6,8], [0,1,2,3,4], [2,2,2,2]]
+"""

Week03/21.py → LinkedList/21_MergeTwoSortedLists.py

@@ -47,3 +47,12 @@ def mergeTwoLists(self, l1, l2):
             merged_list = merged_list.next
 
         return merged_head.next
+
+"""
+[]
+[]
+[1,4,8,12]
+[2,3]
+[1,3,5,7,9]
+[2,4,6,8,10]
+"""

Week03/24.py → LinkedList/24_SwapNodesInPairs.py

@@ -40,3 +40,10 @@ def swapPairs(self, head):
             else:
                 break
         return result.next
+
+"""
+[]
+[1]
+[1,2,3]
+[1,2,3,4,5,6]
+"""

Week03/25.py → LinkedList/25_ReverseNodesIn-k-Group.py

@@ -65,3 +65,12 @@ def reverse_k_nodes(self, before_node, after_node):
         before_node.next = reversed_list_head
         reversed_list_tail.next = after_node
         return reversed_list_tail
+
+"""
+[]
+1
+[1]
+1
+[1,2,3,4,5,6,7,8,9]
+4
+"""

README.md

@@ -19,6 +19,9 @@
 # [Linked List](LinkedList/)
 
 * 02. [Add Two Numbers](LinkedList/02.AddTwoNumbers.py)
+* 21. [Merge Two Sorted Lists](LinkedList/21_MergeTwoSortedLists.py)
+* 24. [Swap Nodes in Pairs](LinkedList/24_SwapNodesInPairs.py)
+* 25. [Reverse Nodes in k-Group](LinkedList/25_ReverseNodesIn-k-Group.py)
 * 61. Rotate List
 * 82. Remove Duplicates from Sorted List II
 * 83. Remove Duplicates from Sorted List
@@ -38,6 +41,9 @@
 * 03. [Longest Substring Without Repeating Characters](HashTable/03_LongestSubstringWithoutRepeatingCharacters.py)
 * 18. `4Sum`
 
+# [Heap](Heap/)
+* 23. [Merge k Sorted Lists](Heap/23_MergeKSortedLists.py)
+
 # [Binary Search](BinarySearch/)
 
 * 69. Sqrt(x)
@@ -57,6 +63,7 @@
 
 # [Backtracking](Backtracking/)
 
+* 22. [Generate Parentheses](Backtracking/23_GenerateParentheses.py)
 * 51. N-Queens
 * 52. N-Queens II
 * 79. Word Search
@@ -87,6 +94,7 @@
 
 # [Stack](Stack/)
 
+* 20. [Valid Parentheses](Stack/20_ValidParentheses.py)
 * 71. [Simplify Path](Stack/71_SimplifyPath.py)
 * 84. [Largest Rectangle in Histogram](Stack/84_LargestRectangleInHistogram.py)
 * 85. [Maximal Rectangle](Stack/85_MaximalRectangle.py)
@@ -117,5 +125,5 @@
 
 # DFA
 
-* 65. [Valid Number](65_ValidNumber.py)
+* 65. [Valid Number](DFA/65_ValidNumber.py)
 

Stack/20_ValidParentheses.py

@@ -0,0 +1,35 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+
+
+class Solution(object):
+    def isValid(self, s):
+        """
+        :type s: str
+        :rtype: bool
+        """
+        parenthes_stack = []
+        match_rule = {")": "(", "]": "[", "}": "{"}
+        for symble in s:
+            if symble == "(" or symble == "[" or symble == "{":
+                parenthes_stack.append(symble)
+
+            else:
+                # Check if stack top matches the current ), ] or }.
+                if (parenthes_stack and
+                        parenthes_stack[-1] == match_rule[symble]):
+                    parenthes_stack.pop()
+                else:
+                    return False
+        # Have some symbles that is not matched.
+        if parenthes_stack:
+            return False
+
+        return True
+
+"""
+""
+"["
+"()()()()[]"
+"()((()){})"
+"""