Open In App

Python Tips and Tricks for Competitive Programming

Improve
Improve
Like Article
Like
Save
Share
Report

Python Programming language makes everything easier and straightforward. Effective use of its built-in libraries can save a lot of time and help with faster submissions while doing Competitive Programming. Below are few such useful tricks that every Pythonist should have at their fingertips:

  • Converting a number into a List of digits using map() Function: 

Below is the implementation to convert a given number into a list of digits:

Python3




# Python program to convert a
# number to a list of digits
 
# Given number
n = 123456
 
# Stores the list of digits
lis = list(map(int, str(n)))
 
# Print the digits
print(lis)


Output: 

[1, 2, 3, 4, 5, 6]

 

  • Converting a sentence into a List of words using split() Function: Below is the implementation to convert a sentence into a list of words:

Python3




# Python program to convert
# a sentence to a list of words
 
# Given sentence
sentence = "GeeksforGeeks is the computer science portal for geeks"
 
# Convert the sentence
# into a list of words
lis = list(sentence.split())
 
# Print the list of words
print(lis)


Output: 

['GeeksforGeeks', 'is', 'the', 'computer', 'science', 'portal', 'for', 'geeks']

 

  • Take newline-separated integers as a List: Newline-separated input from the console can be taken in the form of a List using List Comprehension. Below is the implementation to take input of newline-separated integers as a list:

Python3




# Python program to take
# newline-separated input
# in the form of a list
 
# Given input
n = int(input())
 
lis = [int(input()) for _ in range(n)]


Below is the implementation to demonstrate gcd() function: 

Python3




# Python program to demonstrate gcd() function
import math
a = 8
b = 24
 
# Print the GCD of a and b
print(math.gcd(a, b))


Output: 

8

 

Below is the implementation of the approach:

Python3




# Python program to print all
# permutations using library function
from itertools import permutations
 
# Get all permutations of [1, 2, 3]
perm = permutations([1, 2, 3])
 
# Print the obtained permutations
for i in list(perm):
    print (i)


Output: 

(1, 2, 3)
(1, 3, 2)
(2, 1, 3)
(2, 3, 1)
(3, 1, 2)
(3, 2, 1)

 

  • Printing a string multiple times without Loop: Below is the implementation to print a string multiple times without loop using string multiplication technique:

Python3




# Python program to print
# a string given number of times
 
# Given string
str ="India"
 
# Print the string 2 times
print(str * 2)


Output: 

IndiaIndia

 

  • To print a list with spaces without loop: A list can be printed without running the loop by using the * operator in Python.

Below is the implementation to print a list with spaces without loop: 

Python3




# Python program to print a list with spaces without loop
lis = [1, 2, 3, 4]
 
# Printing list elements with spaces
print(*lis)


Output: 

1 2 3 4

 

Below is the implementation of the above approach: 

Python3




# Python program to convert a
# binary string to its decimal
# equivalent using int() function
 
# Given string
binary = "1010"
 
# Print decimal equivalent
print(int(binary, 2))


Output

10
  • To print sorted list with spaces: Sorting any sequence is very easy in Python using a built-in method sorted() and using * symbol to print list with spaces. Sorted() sorts any sequence (list, tuple) and always returns a list with the elements in a sorted manner, without modifying the original sequence.

Below is the implementation to print a sorted list with spaces: 

Python3




# Python program to print a sorted list with
# spaces using sorted() function
lis = [6, 2, 7, 3, 4]
 
# Print the sorted sequence
print(*sorted(lis))


Output: 

2 3 4 6 7

 

  • To find common elements in two arrays: The common elements in 2 arrays/lists can be done in a much simpler way using sets. The intersection() function in Python gives the common elements in both arrays/lists.

Below is the implementation to demonstrate intersection() function:

Python3




# Python program to print common elements in
# both the list using intersection() function
array1 = [4, 5, 6, 7, 8]
array2 = [3, 4, 5, 1, 72]
 
# Print the common elements
print(set(array1).intersection(set(array2)))


Output

{4, 5}

 



Last Updated : 19 Aug, 2021
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads