Lists in Python - Hacker Rank Solution
Problem
Tutorial :
When we talk about storing multiple values in a container-like data structure, the first thing that comes to mind is a list.You can initialize a list as:
arr = list() # or simply arr = []
or with a few elements as:
arr = [1,2,3]
Elements can be accessed easily similar to most programming languages:
print arr[0] # result is 1 print arr[0] + arr[1] + arr[2] # result is 6
Lists in Python are very versatile. You can add almost anything in a Python list.
In Python, you can create a list of any objects: strings, integers, or even lists. You can even add multiple types in a single list!
Let's look at some of the methods you can use on list.
1.) append(x)
Adds a single element x to the end of a list.
arr.append(9) print arr # prints [1, 2, 3, 9]
2.) extend(L)
Merges another list L to the end.
arr.extend([10,11]) print arr # prints [1, 2, 3, 9, 10, 11]
3.) insert(i,x)
Inserts element x at position i.
arr.insert(3,7) print arr # prints [1, 2, 3, 7, 9, 10, 11]
4.) remove(x)
Removes the first occurrence of element x.
arr.remove(10) arr # prints [1, 2, 3, 7, 9, 11]
5.) pop()
Removes the last element of a list. If an argument is passed, that index item is popped out.
temp = arr.pop() print temp # prints 11
6.) index(x)
Returns the first index of a value in the list. Throws an error if it's not found.
temp = arr.index(3) print temp # prints 2
7.) count(x)
Counts the number of occurrences of an element x.
temp = arr.count(1) print temp # prints 1
8.) sort()
Sorts the list.
arr.sort() print arr # [1, 2, 3, 7, 9]
9.) reverse()
Reverses the list.
arr.reverse() print arr # [9, 7, 3, 2, 1]
Problem
Statement :
Consider a list (list = []). You can perform the following commands:
- insert i e: Insert integer e at position i.
- print: Print the list.
- remove e: Delete the first occurrence of integer e.
- append e: Insert integer e at the end of the list.
- sort: Sort the list.
- pop: Pop the last element from the list.
- reverse: Reverse the list.
Input Format :
The first line contains an integer, n, denoting the number of commands.Each line i of the n subsequent lines contains one of the commands described above.
Constraints :
The elements added to the list must be integers.Output Format :
For each command of type print, print the list on a new line.Sample Input :
12 insert 0 5 insert 1 10 insert 0 6 print remove 6 append 9 append 1 sort print pop reverse print
Sample Output :
[6, 5, 10] [1, 5, 9, 10] [9, 5, 1]
Solution :
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | # Lists in Python - Hacker Rank Solution if __name__ == '__main__': N = int(input()) # Lists in Python - Hacker Rank Solution START Output = []; for i in range(0,N): ip = input().split(); if ip[0] == "print": print(Output) elif ip[0] == "insert": Output.insert(int(ip[1]),int(ip[2])) elif ip[0] == "remove": Output.remove(int(ip[1])) elif ip[0] == "pop": Output.pop(); elif ip[0] == "append": Output.append(int(ip[1])) elif ip[0] == "sort": Output.sort(); else: Output.reverse(); # Lists in Python - Hacker Rank Solution END |
Disclaimer :-
the above hole problem statement is given by hackerrank.com but the solution is generated by the codeworld19 authority if any of the query regarding this post or website fill the following contact form thank you.
CodeWorld19
Hey, I am Parthe Omkar
The solution is provided in Python3, well and good. But, the semicolons(;) are not needed at the end of few lines. It leads to few errors.
if __name__ == '__main__':
N = int(input())
list_test = []
for i in range(N):
input2 = input().split()
if len(input2) == 3:
exec(f"list_test.{input2[0]}({int(input2[1])},{int(input2[2])})")
elif len(input2) == 2:
# print(f"list_test.{input2[0]}({input2[1]})")
exec(f"list_test.{input2[0]}({input2[1]})")
elif input2[0] == 'print' :
exec(f"print({list_test})")
else:
exec(f"list_test.{input2[0]}()")
How to clear a list
do list = []
such a informatic bolg.
sap pp