priority queue

Rearrange string such that no two adjacent characters are same

In this problem, we have to rearrange the characters of the string such that no two adjacent characters are same. To solve this efficiently in O(N log N) time, we will use priority queue data structure.

Data Structures

Leftist Heap

A leftist heap is a modification priority queue implemneted with variant of binary heap. Regarding binary heap, it is always a complete binary tree. It has two main properites Mean Heap Property and Heavy on left side and supports common operations in O(log N) time complexity.

Data Structures

Priority queue is an abstract data type which is like a queue or stack data structure with each element having a priority assigned to it. In priority queue, an element with highest priority assigned is served first, if two elements have same priority then they are served according to enqueue order

C++

Priority Queue in C++ STL

Priority queue in the STL of C++ is a dynamically resizing container to implement the special case of priority queye under the queue data structure. It is a sequential linear container. The top element of the priority queue is the greatest with all elements arranged in non-increasing order.

Algorithms

Cartesian tree sorting

Cartesian tree sorting, also called Levcopoulos Petersson algorithm is an adaptive sorting algorithm, i.e. it performs much better on a partially sorted data. It needs two data structures a Cartesian tree and a priority queue. The algorithm here uses min-heap Cartesian tree to give a sorted sequence