fix few details, linked lists

src/abstract_structures/linked_list/check_pal.py

@@ -1,40 +1,49 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
+#!/usr/bin/python
+
+__author__ = "Mari Wahl"
+__email__ = "marina.w4hl@gmail.com"
 
 ''' Given a linked list, check if the nodes form a palindrome '''
 
-from linked_list_fifo import LinkList, Node
+from linked_list_fifo import LinkedListFIFO, Node
+from node import Node
+
+def isPal(l):
+
+    if len(l1) < 2:
+        return True
+    if l1[0] != l1[-1]:
+        return False
 
-def isPal(l1):
-    if len(l1) < 2: return True
-    if l1[0] != l1[-1]: return False
     return isPal(l1[1:-1])
 
 
 
 def checkllPal(ll):
     node = ll.head
-    l1 = []
+    l = []
+
     while node:
-        l1.append(node.value)   
-        node = node.next
-    return isPal(l1)  
+        l.append(node.value)
+        node = node.pointer
+
+    return isPal(l)
 
 
 
-def main():
-    ll = LinkList()
-    l1 = [1, 2, 3, 2, 1]
-    for i in l1:
-        ll.addNode(i)
-    print(checkllPal(ll))
- 
-    ll.addNode(2)
-    ll.addNode(3)
-    print(checkllPal(ll))
 
 
 if __name__ == '__main__':
-    main()
 
+    ll = LinkedListFIFO()
+    l1 = [1, 2, 3, 2, 1]
+
+    for i in l1:
+        ll.addNode(i)
+
+    assert(checkllPal(ll) == True)
+
+    ll.addNode(2)
+    ll.addNode(3)
+
+    assert(checkllPal(ll) == False)

src/abstract_structures/linked_list/circ_ll.py

@@ -1,72 +0,0 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
-
-
-''' Build a class for a circular linked list and implement a function to see whether
-    a linked list is circular'''
-
-from linked_list_fifo import Node, LinkList
-
-class Node(object):
-    def __init__(self, value = None, next = None):
-        self.value = value
-        self.next = next
-
-
-class CircLinkList(object):
-    def __init__(self):
-        self.head = None
-        self.tail = None
-        self.lenght = 0
-    
-    def addNode(self, value):
-        node = Node(value, self.head)
-        if not self.head:
-            self.head = node
-        if self.tail:
-           self.tail.next = node
-        self.tail = node
-        self.lenght += 1
-        
-    def printList(self):
-        size = self.lenght
-        node = self.head
-        i = 0
-        while i < size:
-            print(node.value)
-            node = node.next   
-            i += 1
-        
-        
- 
-def isCircularll(ll):
-    p1 = ll.head
-    p2 = ll.head
-    
-    while p2 and p2.next:
-        p1 = p1.next
-        p2 = p2.next.next
-        
-        if p1 == p2:
-            return True
-    return False
-
-def main():
-    ll = CircLinkList()
-    for i in range(10):
-        ll.addNode(i)
-    ll.printList()
-    
-    print(isCircularll(ll))
-    
-    ll2 = LinkList()
-    for i in range(10):
-        ll2.addNode(i)
-    ll2.printList() 
-
-    print(isCircularll(ll2)) 
-    
-                   
-if __name__ == '__main__':
-    main()

src/abstract_structures/linked_list/circular_ll.py

@@ -0,0 +1,57 @@
+#!/usr/bin/python
+
+__author__ = "Mari Wahl"
+__email__ = "marina.w4hl@gmail.com"
+
+
+
+''' implement a function to see whether a linked list is circular.
+    To implement this, we just need two pointers with different
+    paces (for example, one goes twice faster)'''
+
+from linked_list_fifo import LinkedListFIFO
+from node import Node
+
+
+class cicularLinkedListFIFO(LinkedListFIFO):
+    def _add(self, value):
+        self.length += 1
+        node = Node(value, self.head)
+        if self.tail:
+            self.tail.pointer = node
+        self.tail = node
+
+
+
+
+def isCircularll(ll):
+    p1 = ll.head
+    p2 = ll.head
+
+    while p2:
+        try:
+            p1 = p1.pointer
+            p2 = p2.pointer.pointer
+        except:
+            break
+
+        if p1 == p2:
+            return True
+    return False
+
+
+
+if __name__ == '__main__':
+
+    ll = LinkedListFIFO()
+    for i in range(10):
+        ll.addNode(i)
+    ll._printList()
+
+    print(isCircularll(ll))
+
+    lcirc = cicularLinkedListFIFO()
+    for i in range(10):
+        lcirc.addNode(i)
+    print(isCircularll(lcirc))
+

src/abstract_structures/linked_list/double_linked_list_fifo.py

@@ -1,53 +1,92 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
+#!/usr/bin/python
 
-''' Implement a double-linked list, which is very simple, we just need inherets from a Linked List Class and  add an attribute for prev.'''
+__author__ = "Mari Wahl"
+__email__ = "marina.w4hl@gmail.com"
+
+''' Implement a double-linked list, which is very simple, we just need inherits
+from a Linked List Class and  add an attribute for previous.'''
+
+from linked_list_fifo import LinkedListFIFO
 
-from linked_list_fifo import LinkList
 
 class dNode(object):
-    def __init__(self, value = None, next = None):
+    def __init__(self, value=None, pointer=None, previous=None):
         self.value = value
-        self.next = next
-        self.prev = None    # THIS IS THE EXTRA ATTRIBUTE FOR DOUBLE L
-        self.children = None    # THIS IS NOT USED HERE, IS EXAMPLES WITH MANY LL INSIDE LLs
-        
-class dLinkList(LinkList):
- 
-    def addNode(self, value):
-        node = dNode(value)
-        if not self.head:
-            self.head = node
-        if self.tail:
-            node.prev = self.tail   # ADD THIS WHEN DOUBLE L
-            self.tail.next = node
-        self.tail = node
-        self.length += 1
+        self.pointer = pointer
+        self.previous = previous
 
 
-    def printListInverse(self): # THIS IS THE EXTRA METHOD FOR DOUBLE L
+class dLinkList(LinkedListFIFO):
+
+    # print each node's value, starting from tail
+    def printListInverse(self):
         node = self.tail
         while node:
             print(node.value)
-            node = node.prev
+            try:
+                node = node.previous
+            except:
+                break
+
+    # add a node in a position different from head,
+    # ie, in the end of the list
+    def _add(self, value):
+        self.length += 1
+        node = dNode(value)
+        if self.tail:
+            self.tail.pointer = node
+            node.previous = self.tail
+        self.tail = node
+
+    # delete a node in some position
+    def _delete(self, node):
+        self.length -= 1
+        node.previous.pointer = node.pointer
+        if not node.pointer:
+            self.tail = node.previous
+
+    # locate node with some index
+    def _find(self, index):
+        node = self.head
+        i = 0
+        while node and i < index:
+            node = node.pointer
+            i += 1
+        return node, i
+
+    # delete nodes in general
+    def deleteNode(self, index):
+        if not self.head or not self.head.pointer:
+            self._deleteFirst()
+        else:
+            node, i = self._find(index)
+            if i == index:
+                self._delete(node)
+            else:
+                print('Node with index {} not found'.format(index))
 
 
 
 
-from collections import Counter
-
-def main():
-  
-    ll = dLinkList()
-    for i in range(1, 10):
-        ll.addNode(i)
-    print('Printing the list...')
-    ll.printList()
-    print('Now, printing the list inversely...')
-    ll.printListInverse()
 
 
 
 if __name__ == '__main__':
-    main()
+
+    from collections import Counter
+
+    ll = dLinkList()
+    for i in range(1, 5):
+        ll.addNode(i)
+    print('Printing the list...')
+    ll._printList()
+    print('Now, printing the list inversely...')
+    ll.printListInverse()
+    print('The list after adding node with value 15')
+    ll._add(15)
+    ll._printList()
+    print("The list after deleting everything...")
+    for i in range(ll.length-1, -1, -1):
+        ll.deleteNode(i)
+    ll._printList()
+

src/abstract_structures/linked_list/find_kth.py

@@ -1,105 +0,0 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
-
-''' Find the mth-to-last element of a linked list.
-    One option is having two pointers, separated by m. P1 start at the roots (p1 = self.root) and p2 is m-behinf pointer, which is created when p1 is at m. When p1 reach the end, p2 is the node. '''
-
-from linked_list_fifo import Node
-
-class LinkList(object):
-    def __init__(self):
-        self.head = None
-        self.tail = None
-        self.lenght = 0
-        
-    def addNode(self, value):
-        node = Node(value)
-        if not self.head:
-            self.head = node
-        if self.tail:
-            self.tail.next = node
-        self.tail = node
-        self.lenght += 1
-        
-    def removeNode(self, index):
-        prev = None
-        node = self.head
-        i = 0
-        while node and i < index:
-            prev = node
-            node = node.next
-            i += 1
-        if i == index:    
-            if not prev:
-                self.head = node.next
-            else:
-                prev.next = node.next
-            self.lenght -= 1
-        else:
-            print('Index not found')       
-        
-    def findkth_from_begin(self, k):
-        node = self.head
-        i = 0
-        while node and i < k:
-            node = node.next
-            i += 1
-        while node:
-            print(node.value)
-            node = node.next
-            
-    def findkth_to_last(self, k):
-        node = self.head
-        key = self.lenght - k
-        i = 0
-        while node and i < key:
-            node = node.next
-            i += 1
-        print(node.value)
-
-    def findkth_to_last_2pointers(self, k):
-        node = self.head
-        pointer = self.head
-        i = 0
-        while pointer and i < k:
-            pointer = pointer.next
-            i += 1
-        while pointer:
-            node = node.next
-            pointer = pointer.next
-        print(node.value)
-        
-    def findkth_to_last_2pointers2(self, k):
-        p1 = self.head
-        p2 = self.head
-        i = 0
-        while p1:
-            if i >= k: # ---> notice >= not >!
-                p2 = p2.next
-            p1 = p1.next
-            i += 1
-        print(p2.value)
-           
-            
-def main():
-    ll = LinkList()
-    for i in range(1, 11):
-        ll.addNode(i)
-    # list is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
-    # so 0th from last is 11, 1th to last is 10, 
-    # 2th from last is 9!
-    
-    
-    print('Finding from begin...')
-    ll.findkth_from_begin(2)    
-    print('Finding to last, case 1...')
-    ll.findkth_to_last(2) #9  
-    print('Finding to last, case 2...')
-    ll.findkth_to_last_2pointers(2)  
-    print('Finding to last, case 3...')
-    ll.findkth_to_last_2pointers2(2)  
-              
-if __name__ == '__main__':
-    main()            
-

src/abstract_structures/linked_list/find_kth_from_the_end.py

@@ -0,0 +1,42 @@
+#!/usr/bin/python
+
+__author__ = "Mari Wahl"
+__email__ = "marina.w4hl@gmail.com"
+
+''' Find the mth-to-last element of a linked list.
+    One option is having two pointers, separated by m. P1 start at the roots
+    (p1 = self.root) and p2 is m-behinf pointer, which is created when p1 is at m.
+    When p1 reach the end, p2 is the node. '''
+
+from linked_list_fifo import LinkedListFIFO
+from node import Node
+
+
+class LinkedListFIFO_find_kth(LinkedListFIFO):
+
+
+    def find_kth_to_last(self, k):
+        p1, p2 = self.head, self.head
+        i = 0
+        while p1:
+            if i > k:
+                try:
+                    p2 = p2.pointer
+                except:
+                    break
+            p1 = p1.pointer
+            i += 1
+        return p2.value
+
+
+
+if __name__ == '__main__':
+    ll = LinkedListFIFO_find_kth()
+    for i in range(1, 11):
+        ll.addNode(i)
+    print('The Linked List:')
+    print(ll._printList())
+    k = 3
+    k_from_last = ll.find_kth_to_last(k)
+    print("The %dth element to the last of the LL of size %d is %d" %(k, ll.length, k_from_last))
+

src/abstract_structures/linked_list/linkedlist.py

@@ -1,65 +0,0 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
-
-from node import Node
-
-class UnorderedList(object):
-    def __init__(self):
-        self.head = None
-
-    def add(self, item):
-        temp = Node(item)
-        temp.setNext(self.head)
-        self.head = temp
-
-    def length(self):
-        current = self.head
-        count = 0
-        while current != None:
-            count = count + 1
-            current = current.getNext()
-        return count
-
-    def search(self, item):
-        current = self.head
-        found = False
-        while current != None and not found:
-            if current.getData() == item:
-                found = True
-            else:
-                current = current.getNext()
-        return found
-
-    def remove(self, item):
-        current = self.head
-        previous = None
-        found = False
-        while not found:
-            if current.getData() == item:
-                found = True
-            else:
-                previous = current
-                current = current.getNext()
-        if previous == None:
-            self.head = current.getNext()
-        else:
-            previous.setNext(current.getNext())
-
-
-def test_UnorderedList(module_name='this module'):
-    llist = UnorderedList()
-    llist.add(31)
-    llist.add(22)
-    llist.add(10)
-    assert(llist.search(22) == True)
-    llist.remove(22)
-    assert(llist.search(22) == False)
-    s = 'Tests in {name} have {con}!'
-    print(s.format(name=module_name, con='passed'))
-
-
-if __name__ == '__main__':
-    test_UnorderedList()
-
-

src/abstract_structures/linked_list/ordered_list.py

@@ -1,97 +0,0 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
-
-
-
-from Node import Node
-
-class OrderedList:
-    """ The structure of an ordered list is a collection of items where each item 
-    holds a relative position that is based upon some underlying characteristic of 
-    the item. The ordering is typically either ascending or descending and we assume 
-    that list items have a meaningful comparison operation that is already defined. 
-    Many of the ordered list operations are the same as those of the unordered list. 
-    """   
-    def __init__(self):
-        self.head = None
-
-
-    def add(self,item):
-        ''' this method is different from linked list '''
-        current = self.head
-        previous = None
-        stop = False
-        while current != None and not stop:
-            if current.getData() > item:
-                stop = True
-            else:
-                previous = current
-                current = current.getNext()
-        temp = Node(item)
-        if previous == None:
-            temp.setNext(self.head)
-            self.head = temp
-        else:
-            temp.setNext(current)
-            previous.setNext(temp)
-    
-    
-    def length(self):
-        current = self.head
-        count = 0
-        while current != None:
-            count = count + 1
-            current = current.getNext()
-        return count
-
-
-    def search(self,item):
-        ''' this method is different from linked list '''
-        current = self.head
-        found = False
-        stop = False
-        while current != None and not found and not stop:
-            if current.getData() == item:
-                found = True
-            else:
-                if current.getData() > item:
-                    stop = True
-                else:
-                    current = current.getNext()
-        return found
-
-
-    def remove(self,item):
-        current = self.head
-        previous = None
-        found = False
-        while not found:
-            if current.getData() == item:
-                found = True
-            else:
-                previous = current
-                current = current.getNext()
-        if previous == None:
-            self.head = current.getNext()
-        else:
-            previous.setNext(current.getNext())
-
-
-
-def test_OrderedList(module_name='this module'):
-    olist = OrderedList()
-    olist.add(31)
-    olist.add(22)
-    olist.add(10)
-    assert(olist.search(22) == True)
-    olist.remove(22)
-    assert(olist.search(22) == False)   
-    s = 'Tests in {name} have {con}!'
-    print(s.format(name=module_name, con='passed'))
-
-
-if __name__ == '__main__':
-    test_OrderedList()
-
-

src/abstract_structures/linked_list/part_linked_list.py

@@ -0,0 +1,58 @@
+#!/usr/bin/python
+
+__author__ = "Mari Wahl"
+__email__ = "marina.w4hl@gmail.com"
+
+''' This function divides a linked list in a value, where everything smaller than this value
+    goes to the front, and everything large goes to the back:'''
+
+
+from linked_list_fifo import LinkedListFIFO
+from node import Node
+
+
+def partList(ll, n):
+
+    more = LinkedListFIFO()
+    less = LinkedListFIFO()
+
+    node = ll.head
+
+    while node:
+        item = node.value
+
+        if item < n:
+            less.addNode(item)
+
+        elif item > n:
+            more.addNode(item)
+
+        node = node.pointer
+
+    less.addNode(n)
+    nodemore = more.head
+
+    while nodemore:
+        less.addNode(nodemore.value)
+        nodemore = nodemore.pointer
+
+    return less
+
+
+
+
+if __name__ == '__main__':
+
+    ll = LinkedListFIFO()
+    l = [6, 7, 3, 4, 9, 5, 1, 2, 8]
+    for i in l:
+        ll.addNode(i)
+
+    print('Before Part')
+    ll._printList()
+
+    print('After Part')
+    newll = partList(ll, 6)
+    newll._printList()
+
+

src/abstract_structures/linked_list/part_ll.py

@@ -1,45 +0,0 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
-
-''' This function partionate a linked list in a value, where everything smaller than this value
-    goes to the front, and everything large goes to the back:'''
-
-from linked_list_fifo import LinkList, Node
-        
-def partList(ll, n):
-    more = LinkList()
-    less = LinkList()
-    node_old = ll.head
-    while node_old:
-        item = node_old.value
-        if item < n:
-            less.addNode(item)
-        elif item > n:
-            more.addNode(item)
-        node_old = node_old.next
-    
-    less.addNode(n)
-    nodemore = more.head
-    while nodemore:
-        less.addNode(nodemore.value)
-        nodemore = nodemore.next  
-    return less
-
-
-
-def main():
-    ll = LinkList()
-    l1 = [6, 7, 3, 4, 9, 5, 1, 2, 8]
-    for i in l1:
-        ll.addNode(i)
-    print('Before Part')    
-    ll.printList()
-    print('After Part')
-    newll = partList(ll, 6)
-    newll.printList()
-   
-                   
-if __name__ == '__main__':
-    main()
-

src/abstract_structures/linked_list/sum_linked_list.py

@@ -0,0 +1,86 @@
+#!/usr/bin/python
+
+__author__ = "Mari Wahl"
+__email__ = "marina.w4hl@gmail.com"
+
+''' Supposing two linked lists representing numbers, such that in each of their
+    nodes they carry one digit. This function sums the two numbers that these
+    two linked lists represent, returning a third list representing the sum:'''
+
+
+from linked_list_fifo import LinkedListFIFO
+from node import Node
+
+
+class LinkedListFIFOYield(LinkedListFIFO):
+
+    # print each node's value, starting from the head
+    def _printList(self):
+        node = self.head
+        while node:
+            yield(node.value)
+            node = node.pointer
+
+
+
+def sumlls(l1, l2):
+
+    lsum = LinkedListFIFOYield()
+    dig1 = l1.head
+    dig2 = l2.head
+    pointer = 0
+
+    while dig1 and dig2:
+        d1 = dig1.value
+        d2 = dig2.value
+        sum_d = d1 + d2 + pointer
+        if sum_d > 9:
+            pointer = sum_d//10
+            lsum.addNode(sum_d%10)
+
+        else:
+            lsum.addNode(sum_d)
+            pointer = 0
+
+        dig1 = dig1.pointer
+        dig2 = dig2.pointer
+
+    if dig1:
+        sum_d = pointer + dig1.value
+        if sum_d > 9:
+            lsum.addNode(sum_d%10)
+        else:
+            lsum.addNode(sum_d)
+        dig1 = dig1.pointer
+
+    if dig2:
+        sum_d = pointer + dig2.value
+        if sum_d > 9:
+            lsum.addNode(sum_d%10)
+        else:
+            lsum.addNode(sum_d)
+        dig2 = dig2.pointer
+
+    return lsum
+
+
+
+
+
+
+if __name__ == '__main__':
+    l1 = LinkedListFIFOYield() # 2671
+    l1.addNode(1)
+    l1.addNode(7)
+    l1.addNode(6)
+    l1.addNode(2)
+
+    l2 = LinkedListFIFOYield() # 455
+    l2.addNode(5)
+    l2.addNode(5)
+    l2.addNode(4)
+
+    lsum = sumlls(l1, l2)
+    l = list(lsum._printList())
+    for i in reversed(l):
+        print i

src/abstract_structures/linked_list/sum_ll.py

@@ -1,70 +0,0 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
-
-''' Supposing two linked lists represening numbers, such that in each of their 
-    nodes they carry one digit. This function sums the two numbers that these
-    two linked lists represent, returning a third list representing the sum:'''
-
-from linked_list_fifo import Node, LinkList
-
-
-def sumlls(l1, l2):
-    lsum = LinkList()
-    dig1 = l1.head
-    dig2 = l2.head
-    next = 0
-    while dig1 and dig2:
-        d1 = dig1.value
-        d2 = dig2.value      
-        sum_d = d1 + d2 + next
-        if sum_d > 9:
-            next = sum_d//10
-            lsum.addNode(sum_d%10)
-            
-        else:   
-            lsum.addNode(sum_d)
-            next = 0
-        
-        dig1 = dig1.next
-        dig2 = dig2.next
-    
-    if dig1:
-        sum_d = next + dig1.value
-        if sum_d > 9:
-            lsum.addNode(sum_d%10)           
-        else:   
-            lsum.addNode(sum_d)   
-        dig1 = dig1.next
-    
-    if dig2:
-        sum_d = next + dig2.value
-        if sum_d > 9:
-            lsum.addNode(sum_d%10)           
-        else:   
-            lsum.addNode(sum_d)   
-        dig2 = dig2.next    
-    
-    
-    return lsum
-
-
-
-def main():
-    l1 = LinkList() # 2671
-    l1.addNode(1)
-    l1.addNode(7)
-    l1.addNode(6)
-    l1.addNode(2)
-    
-    l2 = LinkList() # 455
-    l2.addNode(5)
-    l2.addNode(5)
-    l2.addNode(4)
-    
-    lsum = sumlls(l1, l2)
-    lsum.printList()# 3126
-
-
-if __name__ == '__main__':
-    main()