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diff --git a/‎Python3/022_Generate_Parentheses.py
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+30Lines changed: 30 additions & 0 deletions b/‎Python3/022_Generate_Parentheses.py
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+30Lines changed: 30 additions & 0 deletions
diff --git a/‎Python3/024_Swap_Nodes_in_Pairs.py
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+38Lines changed: 38 additions & 0 deletions b/‎Python3/024_Swap_Nodes_in_Pairs.py
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+38Lines changed: 38 additions & 0 deletions
diff --git a/‎Python3/029_Divide_Two_Integers.py
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+42Lines changed: 42 additions & 0 deletions b/‎Python3/029_Divide_Two_Integers.py
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+42Lines changed: 42 additions & 0 deletions
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+#!usr/bin/env python3
+# -*- coding:utf-8 -*-
+'''
+Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.
+'''
+
+
+class Solution(object):
+    def generateParenthesis(self, n):
+        """
+        :type n: int
+        :rtype: List[str]
+        """
+        result = []
+        self.generate(n, n, "", result)
+        return result
+
+    def generate(self, left, right, string, result):
+        if left == 0 and right == 0:
+            result.append(string)
+            return
+        if left > 0:
+            self.generate(left - 1, right, string + "(", result)
+        if right > left:
+            self.generate(left, right - 1, string + ")", result)
+
+
+if __name__ == "__main__":
+    assert (Solution().generateParenthesis(3)) == ['((()))', '(()())', '(())()', '()(())', '()()()']
+
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+#!usr/bin/env python3
+# -*- coding:utf-8 -*-
+'''
+Given a linked list, swap every two adjacent nodes and return its head.
+
+For example,
+Given 1->2->3->4, you should return the list as 2->1->4->3.
+
+Your algorithm should use only constant space. You may not modify the values in the list, only nodes itself can be changed.
+
+Subscribe to see which companies asked this question
+'''
+
+
+# Definition for singly-linked list.
+class ListNode(object):
+    def __init__(self, x):
+        self.val = x
+        self.next = None
+
+
+class Solution(object):
+    def swapPairs(self, head):
+        """
+        :type head: ListNode
+        :rtype: ListNode
+        """
+        prev = ListNode(-1)
+        prev.next = head
+        temp = prev
+        while temp.next and temp.next.next:
+            node1 = temp.next
+            node2 = temp.next.next
+            temp.next = node2
+            node1.next = node2.next
+            node2.next = node1
+            temp = temp.next.next
+        return prev.next
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+#!usr/bin/env python3
+# -*- coding:utf-8 -*-
+'''
+Divide two integers without using multiplication, division and mod operator.
+
+If it is overflow, return MAX_INT.
+'''
+
+
+class Solution(object):
+    def divide(self, dividend, divisor):
+        """
+        :type dividend: int
+        :type divisor: int
+        :rtype: int
+        """
+        MAX_INT = 2 ** 31 - 1
+        sign = 1
+        if dividend >= 0 and divisor < 0 or dividend <= 0 and divisor > 0:
+            sign = -1
+        dividend = abs(dividend)
+        divisor = abs(divisor)
+
+        result = 0
+        current = divisor
+        currentR = 1
+        while current <= dividend:
+            current <<= 1
+            currentR <<= 1
+        while divisor <= dividend:
+            current >>= 1
+            currentR >>= 1
+            if current <= dividend:
+                dividend -= current
+                result += currentR
+        return min(sign * result, MAX_INT)
+
+
+if __name__ == "__main__":
+    assert Solution().divide(5, -1) == -5
+    # assert Solution().divide(10, 2) == 5
+