Find all triplets with zero sum

def triplets(arr, n):

f = False

for i in range(0, n-2):

for j in range(i+1, n-1):

for k in range(j+1, n):

if (arr[i] + arr[j] + arr[k] == 0):

print(arr[i], arr[j], arr[k])

f = True

if (f == False):

print(" not exist ")

arr = [0, -1, 2, -3, 1]

n = len(arr)

triplets(arr, n)

Interleave the first half of the queue with second half

from queue import Queue

def interLeaveQueue(q):

if (q.qsize() % 2 != 0):

print("Input even number of integers.")

s = []

size = int(q.qsize() / 2)

for i in range(size):

s.append(q.queue[0])

q.get()

while len(s) != 0:

q.put(s[-1])

s.pop()

for i in range(size):

q.put(q.queue[0])

q.get()

for i in range(size):

s.append(q.queue[0])

q.get()

while len(s) != 0:

q.put(s[-1])

s.pop()

q.put(q.queue[0])

q.get()

if __name__ == '__main__':

q = Queue()

q.put(11)

q.put(12)

q.put(13)

q.put(14)

q.put(15)

q.put(16)

q.put(17)

q.put(18)

q.put(19)

q.put(20)

interLeaveQueue(q)

length = q.qsize()

for i in range(length):

print(q.queue[0], end=" ")

q.get()

Find size of Doubly Linked List

class Nodes:

def __init__(self):

self.data = None

self.next = None

self.prev = None

def push( ref, new_data):

new_node = Nodes()

new_node.data = new_data

new_node.next = (ref)

new_node.prev = None

if ((ref) != None):

(ref).prev = new_node

(ref) = new_node

return ref

def findSize(node):

res = 0

while (node != None):

res = res + 1

node = node.next

return res

head = None

head = push(head, 4)

head = push(head, 3)

head = push(head, 2)

head = push(head, 1)

print(findSize(head))

Spiral Square Mania with Turtle

import turtle as t

pen = t.Turtle()

pen.color("cyan")

pen.speed(0)

colors = ["green","black","orange","navy","green","black","orange","navy"]

def draw_square(color):

        for side in range(4):

                pen.forward(100)

                pen.right(90)

                for side in range(4):

                        pen.forward(50)

                        pen.right(90)

pen.penup()

pen.back(40)

pen.pendown()

for color in colors:

        pen.color(color)

        draw_square(color)

        pen.forward(50)

        pen.left(45)

pen.hideturtle()

t.done()

Chess-Board using Turtle

import turtle

sc = turtle.Screen()

cb = turtle.Turtle()

def draw():

    for i in range(4):

        cb.forward(30)

        cb.left(90)

    cb.forward(30)

if __name__ == "__main__":

    sc.setup(400, 600)

    cb.speed(100)

    for i in range(8):

        cb.up()

        cb.setpos(-100, 30 * i)

        cb.down()

        for j in range(8):

            if (i + j) % 2 == 0:

                col = 'black'

            else:

                col = 'white'

            cb.fillcolor(col)

            cb.begin_fill()

            draw()

            cb.end_fill()

    cb.hideturtle()

    turtle.done()