A binary search tree is a type of ordered binary tree, where the left child has a value smaller than its parent, and the right child has a value greater than or equal to its parent. In a binary search tree, a node has two references, the left child and …
A circular queue is a queue in which all elements are connected to form a circular. A circular queue can be implemented with an array or a linked list. In the array implementation, the index of the rear element wraps around to the beginning of the array. In this post, …
Permutation of multiple arrays and iterator has two tasks. First is the permutation of multiple arrays and output as an array of new combinations. The second is to implement the iterator of this new array. Permutation is an important topic in the fields of combinatorics. It is usually implemented using …
A trie is a tree-like data structure in which every node stores a character. A trie can store multiple words. After building a trie, strings or substrings can be retrieved by traversing down a path (a branch) of the trie. Tries are used to find substrings, autocomplete and many other …
Delete files older than n days and remove the empty directories after the files are deleted. This can be done using recursion. Recursion is a technique that a function calls itself. When the base condition is met, the rest of call stacks return from the last call to the first. …
To sort squares of a sorted array, you don’t want to use any sorting algorithms such as bubble sort. Because it takes O(nlogn) ~ O(n^2) time. Here we introduce a better way to sort in one pass. The solution is using two pointers. Initialize two pointers, one points to the …
A binary search tree is an ordered binary tree. The left subtree contains nodes whose keys are less than the node’s key value, while the right subtree contains nodes whose keys are greater than or equal to the node’s key value. Moreover, both subtrees are also binary search trees. A binary search …
A trie is a tree-like data structure in which every node stores a character. A trie can store multiple words. After building a trie, strings or substrings can be retrieved by traversing down a path (a branch) of the trie. Insert a word in a trie, search a word, or …
A trie is a tree-like data structure in which every node stores a character. A tire can store one or multiple words. After building a trie, strings or substrings can be retrieved by traversing down a path (a branch) of the trie. Tries are used to find substrings, autocomplete and …
Hash table is a data structure that can map keys to values. A hash table uses a hash function to compute a key into an integer (hash value), which indicates the index of the buckets (aka array). From the key, the correct value can be stored and found. The time …
