Strings/Arrays/Lists

Contains some common questions and algorithms related to strings or 1-d arrays/lists.

Topic/Question	Code in Python	Code in C++
Find the longest substring with k unique characters in a given string	py	-
Find a pattern in a string using KMP search algorithm	py	-
Find the Kth smallest element in the array	py	-
Find a pair in an array with sum x	py	-
Print all valid (properly opened and closed) combinations of n pairs of parentheses	py	-
reverse the order of the words in the array	py	-
Find index of given number in a sorted array shifted by an unknown offset	py	-
Print all permutations of a given string	py	-

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Dynamic Programming

Contains some popular questions based on dynamic programming approach.

Topic/Question	Code in Python	Code in C++
0-1 Knapsack Problem	py	-
Cutting Rod problem	py	-
minimum number of edits (operations) required to convert ‘str1’ into ‘str2’	py	-
Given a 2-D matrix of 0s and 1s, find the Largest Square which contains all 1s in itself	py	-
Given two sequences, print the longest subsequence present in both of them.	py	-
Length of the longest subsequence in an array such that all elements of the subsequence are sorted in increasing order	py	-
Find minimum cost path in a matrix from (0,0) to given point (m,n)	py	-
Partition a set into two subsets such that the difference of subset sums is minimum	py	-
Minimum number of umbrellas of m different sizes required to accomodate N people	py	cpp
Determine if there is a subset of the given set with sum equal to given sum	py	-
Maximum Subarray Problem	py	-
Given a distance ‘dist, count total number of ways to cover the distance with 1, 2 and 3 steps	py	-

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Graph

Contains implementation of Graph data structure and some common questions and algorithms related to it.

Topic/Question	Code in Python	Code in C++
Find all possible words in a board of characters	py	-
Breadth First Search Traversal	py	-
Depth First Search Traversal	py	-
Detect Cycle in directed graph	py	-
Detect cycle in undirected graph	py	-
Dijkstra’s Shortest Path Algorithm	py	-
Find shortest distances between each pair of vertices in a given edge weighted directed Graph	py	-
Graph implementation	py	-
Kruskal's Algorithm for Minimum Spanning Tree	py	-
Topological Sort	py	-

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Linked List

Contains implementation of Linked List data structure and some common questions and algorithms related to it.

Singly Linked List

Topic/Question	Code in Python	Code in C++
Clone a linked list with next and random pointer	py	-
Given a linked list of line segments, remove middle points if any	py	-
Construct a Maximum Sum Linked List out of two Sorted Linked Lists having some Common nodes.	py	-
Merge a linked list into another linked list at alternate positions	py	-
Perform Merge Sort	py	-
Find Middle Node	py	cpp
Point to next higher value node in a linked list with an arbitrary pointer	py	-
Find if linked list contains any cycle	py	-
To select a random node in a singly linked list	py	-
Find and remove cycle if any	py	cpp
Reverse sub list of K nodes each	py	cpp
Reverse alternate sub list of K nodes each	py	cpp
Reverse a linked list	py	cpp
Bring even valued nodes to the front	py	-
Implementation of Singly Linked List	py	cpp
Skip M nodes and then delete N nodes alternately	py	cpp

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Matrix

Contains some common algorithms and questions based on Matrix.

Topic/Question	Code in Python	Code in C++
Given the Coordinates of King and Queen on a chessboard, check if queen threatens the king	py	-
Search in a row wise and column wise sorted matrix	py	-
Given a 2D array, print it in spiral form	py	-

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Tree

Contains implementation of Tree data structure and some common questions and algorithms related to it.

Binary Search Tree

Topic/Question	Code in Python	Code in C++
Binary Search Tree implementation	py	-
Check if a given array can represent Preorder Traversal of Binary Search Tree	py	-
Find the in-order ancestor of a given node in BST	py	-
Find the Lowest Common Ancestor	py	-
Given a sorted array, create a BST with minimal height	py	-

Binary Tree

Topic/Question	Code in Python	Code in C++
Print Nodes in Bottom View of Binary Tree	py	-
Check if a binary tree is height balanced	py	-
Check whether a binary tree is a full binary tree or not	py	-
Given two binary trees, check if the first tree is subtree of the second one	py	-
Find the Lowest Common Ancestor in a Binary Tree	py	-
Create a list of all nodes at each depth	py	-
Find the maximum path sum i.e. max sum of a path in a binary tree	py	-
Find minimum depth of a binary tree	py	-
Remove nodes on root to leaf paths of length < K	py	-
Given a Perfect Binary Tree, reverse the alternate level nodes of the tree	py	-
Print Nodes in Top View of Binary Tree	py	-

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