120+ Common Code and Interview Problems Solved in Python

Master the most common code and interview problems in Python with this comprehensive guide. Learn how to solve real-world programming problems with Python and ace your next interview.

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Problem	Link
Given an array of integers, find the pair of adjacent elements that has the largest product and return that product.	adjacentElementProduct.py
Convert the string "123" into 123, without using the built-api `int()`	atoi.py
Given an array , find if the number exists, develop a `recursive` implementation of the binary search. If the element is not found it returns -1	binary_search_recursive.py
Bresenham Line Algorithm (BLA) is one of the earliest algorithms developed in computer graphics. It is used for drawing lines	bresenham_line_algorithm.py
Find the no. of nodes in a BST that lies in a given range	bst_nodes_in_range.py
Bubble Sort	bubbleSort.py
Find the angle made by the hour hand and the minute hand at any given time. Assume it is an analog clock	calculateClockAngle.py
Two strings of sizes m and n are given, we have to find how many characters need to be removed from both the string so that they become anagrams of each other	check_anagrams.py
Find the numbers which are semiprimes, within a given range. A semiprime is a product of two prime numbers, not necessarily distinct. Squares of prime numbers are also semiprimes.	check_semiprime.py
Given a graph, there are two methods to perform traversal on it 1. Depth First Search (DFS) 2. Breadth First Search (BFS)	dfs_bfs.py
The diameter of a tree (sometimes called the width) is the number of nodes on the longest path between two end nodes(leftmost leaf node and rightmost leaf node).	diameterOfTree.py
Estimate pi using random distribution	estimate_pi.py
Write an efficient program for printing k largest elements in an array. Elements in array can be in any order.	find_k_largest.py
Given a linked list, this method will return m'th element to the last 2->3->4->8->5; m=2 will return 8 since 8 is second to last	find_m_to_last_llist.py
Given an array of numbers, find all the pairs of numbers which sum upto `k`	find_pairs_sum_k.py
Given an array of numbers, find all the pairs of numbers whose product is `k`	find_products_pair_k.py
Given an array of integers, write a function that returns true if there is a triplet (a, b, c) that satisfies a^2 + b^2 = c^2.	find_pythagoras_triplet.py
Given a binary tree, find the second largest node in it	find_second_largest_in_binary_tree.py
Write a function that computes the list of the first 100 Fibonacci numbers	first_n_fibo.py
Given an input string, it gives the first non repeating character in it	first_non_repeating.py
Given an input string, find the first recurring character in it.	first_recurring_character.py
Given a string, find the first non-repeating character in it. For example, if the input string is “GeeksforGeeks”, then output should be ‘f’ and if input string is “GeeksQuiz”, then output should be ‘G’.	first_unique_letter.py
Write a function that given a list of non negative integers, arranges them such that they form the largest possible number. For example, given [50, 2, 1, 9], the largest formed number is 95021	gen_largest_num_frm_list.py
Tree Data Structure in Python	general_tree_structure.py
Given the arrival and departure times of all trains that reach a railway station, the task is to find the minimum number of platforms required for the railway station so that no train waits. We are given two arrays that represent the arrival and departure times of trains that stop.	getMinPlatforms.py
Print duplicate characters in a string	get_dup_chars.py
Check if a given array has zero sum sub array	hasZeroSumSubArray.py
Given a string, check if it only contains digits	has_only_digits.py
Given two lat, long coordinates , calculate `Haversine` distance between them	haversine.py
Heap Data Structure	heap_structure.py
Print numbers 1 to 100 without using any numbers or integers	hundred_without_int.py
Write a program to convert interger to Roman Representation	interger_to_roman_num.py
Given two sorted array of sizes m and n in which all elements are distinct. Find the common elements between them	intersection_arrays.py
Check if a matrix is symmetric or not	isMatrixSymmetric.py
Check if two strings are anagrams of each other	is_anagram.py
Check if two strings are anagrams of each other	is_anagram_using_collections.py
Write a program to check if a number is a palindrome or not	is_num_palindrome.py
Given a string, return True if it is a numeric data type, False otherwise	is_numeric.py
N soldiers are standing in a circle and first person has sword and he kills the 2nd person and gives the sword to the third person and so on till 99th person kills the 100th person gives the sword back to the first person, this goes on till only one person survives. Print the survivor.	josephus.py
The effective time complexity of this improved version is O(logN). For the problem statement, refer `josephus.py`	josephus_improved.py
The effective time complexity of this improved version is O(1). For the problem statement, refer `josephus.py`	josephus_improved_v3.py
Implement the Karatsuba algorithm	karatsuba.py
Implement Level Order traversal for a binary tree	level_order_tree.py
Linked List Data Structure	linked_list_data_structure.py
Detect if a linked list has a loop	loop_in_linkedlist.py
Find the Lowest Common ancestor between two nodes in a binary search tree. Let T be a rooted tree. The lowest common ancestor between two nodes n1 and n2 is defined as the lowest node in T that has both n1 and n2 as descendants (where we allow a node to be a descendant of itself). The LCA of n1 and n2 in T is the shared ancestor of n1 and n2 that is located farthest from the root.	lowest_common_ancestor.py
A majority element in an array A[] of size n is an element that appears more than n/2 times. Find the majority element in the given array.	majority_element.py
Find the max number in an array without using built-in functions	max_in_array.py
Given a list of positive and negative numbers, find the maximum subarray sum. Constraint: Solve it in O(n)	maximum_subarray_sum.py
Implementation of Merge Sort	merge_sort.py
Find the minimum and maximum numbers in an array in a single loop	min_max_array_oneLoop.py
Given an array of integers we need to move all the zeroes to the end and maintain the order of rest of the elements. Needless to say it should be an in-place solution	move_zeros_to_end.py
Print the nodes of a binary tree which do not have a sibling	no_sibling_tree.py
Let all odd numbers come before even numbers, and sort the odd numbers in ascending order and even numbers in descending order. For example, the string '1982376455' becomes '1355798642'	oddAscEvenDesc.py
Compute and print the pascal traingle, given the no. of levels	pascal_triangle.py
using factorial, reduced the time complexity of program from O(2^N) to O(N)	pascals_triangle_improved.py
Print the permutations of a string	permutations.py
Print the permutatations of a string (Simplified)	permute_strings.py
Preorder Traversal of a Binary Search Tree in Iterative fashion	preorder_iterative_bst.py
Implementation of a priority Queue	priority_queue_simple.py
Process the string "k:1	k1:2
Given an array arr[] of n integers, construct a Product Array prod[] (of same size) such that prod[i] is equal to the product of all the elements of arr[] except arr[i].	product_puzzle.py
Implementation of a Queue Data Structure	queue_data_structure.py
Implementation of Quick Sort	quick_sort.py
Write an efficient function that deletes characters from an ASCII string where any character existing in remove must be deleted from str. For example, given a str of "Battle of the Vowels: Hawaii vs. Grozny" and a remove of "aeiou", the function should transform str to “Bttl f th Vwls: Hw vs. Grzny”.	remove_chars.py
Remove duplicate characters from string	remove_dup_chars.py
Remove duplicates using a dictionary	remove_duplicates.py
Remove duplicates using extra space	remove_duplicates_v2.py
Reverse the string in place	reverse_in_place.py
Reverse the string using recursion	reverse_str_recursive.py
Given a sentence, reverse each word but don't reverse the sentence	reverse_words.py
Given a matrix, rotate it by 180 degree	rotateMatrix180Deg.py
Find Median from Data Stream of integers	running_median_integers.py
Given a sorted array in which all elements appear twice (one after one) and one element appears only once. Find that element Constraints: in O(log n) complexity.	search_unique.py
A simple implementation of Selection Sort	selection_sort.py
A simple implementation of Stack Data Structure	stack_data_structure.py
The span Si of the stock’s price on a given day i is defined as the maximum number of consecutive days just before the given day, for which the price of the stock on the current day is less than or equal to its price on the given day. Problem: We have a series of n daily price quotes for a stock and we need to calculate span of stock’s price for all n days	stock_span.py
Write a program to sum a given array using recursion	sum_array_recursion.py
You are getting two streams of data with dates as key, merge the two streams and return average of the values if there is a common date else just update the value as received in the stream, refer example in the code	timeseries.py
Given two sorted array of sizes m and n in which all elements are distinct. Find the union between them Constraints: in O(m+n) complexity.	union_arrays.py
Username validation program	username_validation.py
Given an array of integers(+ve,-ve and 0) find the sign of the product of all the given values.	signOfProduct.py

Problems available: Solved -- 63 ; Newly Added -- 57

1. Code Style is added

2. 57 new problems are added in `Interview_Questions.md`. Solutions to be uploaded soon.

alt text 40+ Common code and interview problems solved in Python (it's growing...)

The core idea is not to utilize built-in functions or library and giving it a more logic-based approach, so that it can be language-friendly and not end up being another repository of "Python Tips and Tricks" .

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Consistent formatting (using Black)
It can compile in its current state (and there are relatively no issues)

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LICENSE

MIT License

View on GitHub: https://github.com/devAmoghS/Python-Interview-Problems-for-Practice

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