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#### Implement graph as adjacency list

A graph is a data structure that consists of a set of nodes connected by edges. Graphs are used to ...

#### Implement weighted graph as adjacency list

A graph is a data structure that consists of a set of nodes connected by edges. Graphs are used to ...

#### Shortest path from source to destination in matrix – Code

Shortest path in matrix is to find the shortest distance from the the source to the destination. As you know, ...

#### Shortest path and 2nd shortest path using Dijkstra – code

What is Dijkstra's algorithm? Dijkstra's algorithm is an algorithm to find the shortest paths between vertices in a graph. It ...

#### Build hierarchy tree – Code

Build hierarchy tree reads employee data and build a corporation hierarchy tree from the list. HashMap plays important role to ...

#### Depth first search in matrix using recursion

An adjacency matrix is a 2d array representing a graph. The nodes are the headings for the rows and columns ...

#### Autocomplete with trie (3 solutions) – Code

Autocomplete is a feature that search box returns the suggestions based on what you have typed. Autocomplete with trie provides ...

#### Prefix to postfix (2 solutions) – stack and recursion

In mathematics expressions, there are infix, prefix and postfix notations. Infix notation is characterized by the placement of operators between ...

#### Find K closest points to origin (3 solutions) – Time complexity explained

The K closest problem is to find K closest points to the pointer(0,0) (it is called center or origin). The ...

#### Huffman coding and decoding – Step by step

What is huffman coding? Huffman coding is an algorithm to generate the binary code based on the frequencies of corresponding ...