Merge pull request #23 from AbhiSaphire/pc-upload

Linked List

Coding Club India/Asked Amazon Interview Questions/Add2NumberLL.py

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+def reverse(ll):
+    curr = ll
+    forward = prev = None
+    while curr != None:
+        forward = curr.next
+        curr.next = prev
+        prev = curr
+        curr = forward
+    ll = prev
+    return ll
+
+def addLists(first, second):
+    first = reverse(first)
+    second = reverse(second)
+    prev = None
+    temp = None
+    carry = 0 
+    res = LinkedList()
+    while(first is not None or second is not None): 
+        fdata = 0 if first is None else first.data 
+        sdata = 0 if second is None else second.data 
+        Sum = carry + fdata + sdata 
+        carry = 1 if Sum >= 10 else 0
+        Sum = Sum if Sum < 10 else Sum % 10
+        temp = Node(Sum) 
+
+        if res.head is None: 
+            res.head = temp 
+        else : 
+            prev.next = temp 
+
+        prev = temp 
+
+        if first is not None: 
+            first = first.next
+        if second is not None: 
+            second = second.next
+
+    if carry > 0: 
+        temp.next = Node(carry)
+
+    res.head = reverse(res.head)
+    return res.head
+
+# Input - 4 5, 3 4 5 || Output - 3 9 0
+# Explanation - 
+#           4->5
+#        3->4->5
+#        -------
+#        3->9->0

Coding Club India/Asked Amazon Interview Questions/DeleteMidLL.py

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+'''
+class Node:
+    def __init__(self, data):
+        self.data = data
+        self.next = None
+'''
+def deleteMid(head):
+    '''
+    head:  head of given linkedList
+    return: head of resultant llist
+    '''
+    if head == None or head.next == None:
+        return None
+
+    slow = fast = prev = head
+    while slow and fast and fast.next:
+        prev = slow
+        slow = slow.next
+        fast = fast.next.next
+
+    prev.next = slow.next
+
+    return head

Coding Club India/Asked Goldman Sach Interview Questions/DeleteWithoutHeadPointer.py

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+#User function Template for python3
+'''
+    Your task is to delete the given node from
+	the linked list, without using head pointer.
+	
+	Function Arguments: node (given node to be deleted) 
+	Return Type: None, just delete the given node from the linked list.
+
+	{
+		# Node Class
+		class Node:
+		    def __init__(self, data):   # data -> value stored in node
+		        self.data = data
+		        self.next = None
+	}
+
+	Contributed By: Nagendra Jha
+'''
+def deleteNode(curr_node):
+    temp = curr_node.next
+    curr_node.data = temp.data
+    curr_node.next = temp.next
+    temp = None

Coding Club India/Asked Goldman Sach Interview Questions/MergeSortLL.py

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+def split(tempHead): 
+    fast = slow = tempHead 
+    while(True): 
+        if fast.next is None: 
+            break
+        if fast.next.next is None: 
+            break
+        fast = fast.next.next 
+        slow = slow.next
+
+    temp = slow.next
+    slow.next = None
+    return temp
+
+def merge(first, second): 
+
+    # If first linked list is empty 
+    if first is None: 
+        return second  
+
+    # If secon linked list is empty  
+    if second is None: 
+        return first 
+
+    # Pick the smaller value 
+    if first.data < second.data: 
+        first.next = merge(first.next, second) 
+        first.next.prev = first 
+        first.prev = None   
+        return first 
+    else: 
+        second.next = merge(first, second.next) 
+        second.next.prev = second 
+        second.prev = None
+        return second
+
+def sortDoubly(tempHead):
+    if tempHead is None:  
+        return tempHead 
+    if tempHead.next is None: 
+        return tempHead 
+
+    second = split(tempHead) 
+
+    # Recur for left and righ halves 
+    tempHead = sortDoubly(tempHead) 
+    second = sortDoubly(second) 
+
+    # Merge the two sorted halves 
+    return merge(tempHead, second)

Coding Club India/Asked Goldman Sach Interview Questions/QuickSortDLL.cpp

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+// CPP
+// Partition Function for QuickSort in Doubly Linked List
+// Asked in Goldman Sachs and HSBC Interview Questions
+
+struct Node partition(Node *l, Node *h){
+    int x = h->data;  
+
+    // similar to i = l-1 for array implementation  
+    Node *i = l->prev;  
+
+    // Similar to "for (int j = l; j <= h- 1; j++)"  
+    for (Node *j = l; j != h; j = j->next)  
+    {  
+        if (j->data <= x)  
+        {  
+            // Similar to i++ for array  
+            i = (i == NULL)? l : i->next;  
+
+            swap(&(i->data), &(j->data));  
+        }  
+    }  
+    i = (i == NULL)? l : i->next; // Similar to i++  
+    swap(&(i->data), &(h->data));  
+    return i;
+}

Coding Club India/Asked Microsoft Interview Questions/Add2NumberLL.py

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+def reverse(ll):
+    curr = ll
+    forward = prev = None
+    while curr != None:
+        forward = curr.next
+        curr.next = prev
+        prev = curr
+        curr = forward
+    ll = prev
+    return ll
+
+def addLists(first, second):
+    first = reverse(first)
+    second = reverse(second)
+    prev = None
+    temp = None
+    carry = 0 
+    res = LinkedList()
+    while(first is not None or second is not None): 
+        fdata = 0 if first is None else first.data 
+        sdata = 0 if second is None else second.data 
+        Sum = carry + fdata + sdata 
+        carry = 1 if Sum >= 10 else 0
+        Sum = Sum if Sum < 10 else Sum % 10
+        temp = Node(Sum) 
+
+        if res.head is None: 
+            res.head = temp 
+        else : 
+            prev.next = temp 
+
+        prev = temp 
+
+        if first is not None: 
+            first = first.next
+        if second is not None: 
+            second = second.next
+
+    if carry > 0: 
+        temp.next = Node(carry)
+
+    res.head = reverse(res.head)
+    return res.head
+
+# Input - 4 5, 3 4 5 || Output - 3 9 0
+# Explanation - 
+#           4->5
+#        3->4->5
+#        -------
+#        3->9->0

Coding Club India/Asked Microsoft Interview Questions/DeleteMidLL.py

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+'''
+class Node:
+    def __init__(self, data):
+        self.data = data
+        self.next = None
+'''
+def deleteMid(head):
+    '''
+    head:  head of given linkedList
+    return: head of resultant llist
+    '''
+    if head == None or head.next == None:
+        return None
+
+    slow = fast = prev = head
+    while slow and fast and fast.next:
+        prev = slow
+        slow = slow.next
+        fast = fast.next.next
+
+    prev.next = slow.next
+
+    return head

Coding Club India/Asked Microsoft Interview Questions/SortedInsertCircularLL.py

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+def sortedInsert(current, data):
+    '''
+    current:  head of given sorted circular linked list
+    data:  data to be inserted
+    
+    return: head of resultant circular linked list
+    '''
+    new_node = Node(data)
+    if current is None: 
+        new_node.next = new_node  
+        return new_node
+
+    head = current
+    if (current.data >= new_node.data): 
+        while current.next != head : 
+            current = current.next
+        current.next = new_node 
+        new_node.next = head 
+        head = new_node
+        return head
+
+    else: 
+        while (current.next != head and 
+            current.next.data < new_node.data): 
+            current = current.next
+
+        new_node.next = current.next
+        current.next = new_node
+        return head
+
+# Input - 1 2 4, 2      || Output - 1 2 2 4
+# Explanation - 
+#   1->2->4  :: Since 2 (to be inserted value) is 2<=2<4
+#   1->2->2->4

Coding Club India/Interview Questions/Powerof4.py

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+def powerof4(n):
+	if not n&3:
+		return "True"
+	return "False"
+
+if __name__ == "__main__":
+	t = int(input())
+	for i in range(t):
+		n = int(input())
+		print(powerof4(n))

Coding Club India/Interview Questions/Split2CircularLL.cpp

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+void splitList(Node *head, Node **head1_ref, Node **head2_ref)
+{
+    Node *slow_ptr = head;  
+    Node *fast_ptr = head;  
+
+    if(head == NULL)  
+        return;  
+
+    /* If there are odd nodes in the circular list then  
+       fast_ptr->next becomes head and for even nodes  
+       fast_ptr->next->next becomes head */
+    while(fast_ptr->next != head &&  
+          fast_ptr->next->next != head)  
+    {  
+        fast_ptr = fast_ptr->next->next;  
+        slow_ptr = slow_ptr->next;  
+    }  
+
+    /* If there are even elements in list 
+       then move fast_ptr */
+    if(fast_ptr->next->next == head)  
+        fast_ptr = fast_ptr->next;  
+
+    /* Set the head pointer of first half */
+    *head1_ref = head;  
+
+    /* Set the head pointer of second half */
+    if(head->next != head)  
+        *head2_ref = slow_ptr->next;  
+
+    /* Make second half circular */
+    fast_ptr->next = slow_ptr->next;  
+
+    /* Make first half circular */
+    slow_ptr->next = head;
+}