# Category Archives: Source Code

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

## 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 uses greedy technique by picking the un-visited vertex with the lowest distance. When all vertices have been evaluated, the result is the shortest path. Find 2nd shortest path is a …

## Build hierarchy tree – Code

## Depth first search in matrix using recursion

## 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 an implementation of auto-complete by using data structure trie. A trie is a tree-like data structure in which every node stores a character. After building the trie, strings or substrings …

## 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 operands. For example, the plus sign in 2 + 2. Prefix notation is a notation in which operators precede their operands, such as + 3 4. Postfix notation is a …

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

## Huffman coding and decoding – Step by step

By applying huffman algorithms, we compress the input string by using the generated code. We can also use the code to decompress to get the original string. Here are the steps of huffman coding and decoding. The code is available in Java, JavaScript and Python. Amazon Interview Question(modified) Implement the …