Collections.deque() in Python | HackerRank Solution

Hello coders, today we are going to solve Collections.deque() HackerRank Solution in Python.

Objective

Collections.deque()

A deque is a double-ended queue. It can be used to add or remove elements from both ends.

Deques support thread safe, memory efficient appends and pops from either side of the deque with approximately the same O(1) performance in either direction.

Example

Code

>>> from collections import deque
>>> d = deque()
>>> d.append(1)
>>> print d
deque([1])
>>> d.appendleft(2)
>>> print d
deque([2, 1])
>>> d.clear()
>>> print d
deque([])
>>> d.extend('1')
>>> print d
deque(['1'])
>>> d.extendleft('234')
>>> print d
deque(['4', '3', '2', '1'])
>>> d.count('1')
1
>>> d.pop()
'1'
>>> print d
deque(['4', '3', '2'])
>>> d.popleft()
'4'
>>> print d
deque(['3', '2'])
>>> d.extend('7896')
>>> print d
deque(['3', '2', '7', '8', '9', '6'])
>>> d.remove('2')
>>> print d
deque(['3', '7', '8', '9', '6'])
>>> d.reverse()
>>> print d
deque(['6', '9', '8', '7', '3'])
>>> d.rotate(3)
>>> print d
deque(['8', '7', '3', '6', '9'])

Task

Perform append, pop, popleft and appendleft methods on an empty deque d.

Input Format

The first line contains an integer N, the number of operations.
The next N lines contains the space separated names of methods and their values.

Constraints

• 0 < N <= 100

Output Format

Print the space separated elements of deque d.

Sample Input

6
append 1
append 2
append 3
appendleft 4
pop
popleft

Sample Output

1 2

Solution – Collections.deque() in Python

# Enter your code here. Read input from STDIN. Print output to STDOUT
from collections import deque

D = deque()

for _ in range(int(input())):
    oper, val, *args = input().split() + ['']
    eval(f'D.{oper} ({val})')
print(*D)

Disclaimer: The above Problem (Collections.deque()) is generated by Hacker Rank but the Solution is Provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.