Source code are the collections of coding interview questions and their source code. Click the title you are interested, you will find the download link of the source code. Cannot find what you want? Please check out my github and my Java coding book.

Flow network and min cut
A flow network is a directed graph where each edge has a capacity and each edge receives a flow. The ...
Read More
Read More

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, ...
Read More
Read More

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 ...
Read More
Read More

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

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 ...
Read More
Read More

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 ...
Read More
Read More

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 ...
Read More
Read More

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 ...
Read More
Read More

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 ...
Read More
Read More

Hierholzer’s algorithm to find Euler path – undirected graph
An Euler path is a trail in a graph that visits every edge exactly once. Here we use graph data ...
Read More
Read More