Book Image

R Data Structures and Algorithms

By : PKS Prakash, Achyutuni Sri Krishna Rao
Book Image

R Data Structures and Algorithms

By: PKS Prakash, Achyutuni Sri Krishna Rao

Overview of this book

In this book, we cover not only classical data structures, but also functional data structures. We begin by answering the fundamental question: why data structures? We then move on to cover the relationship between data structures and algorithms, followed by an analysis and evaluation of algorithms. We introduce the fundamentals of data structures, such as lists, stacks, queues, and dictionaries, using real-world examples. We also cover topics such as indexing, sorting, and searching in depth. Later on, you will be exposed to advanced topics such as graph data structures, dynamic programming, and randomized algorithms. You will come to appreciate the intricacies of high performance and scalable programming using R. We also cover special R data structures such as vectors, data frames, and atomic vectors. With this easy-to-read book, you will be able to understand the power of linked lists, double linked lists, and circular linked lists. We will also explore the application of binary search and will go in depth into sorting algorithms such as bubble sort, selection sort, insertion sort, and merge sort.
Table of Contents (17 chapters)
R Data Structures and Algorithms
Credits
About the Authors
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface

Exercises


  1. What will be the top value for the following stack operations?

          PUSH(1) 
          PUSH(2) 
          PUSH(6) 
          PUSH(3) 
          POP() 
          POP()
    
  2. Assume a stack with the elements {1, 2, 3, 5, 6, 7} in order, with 7 on top. Write the operations required to insert 4 after 3 in the current stack.

  3. Explain the difference in the outputs of the following recursion functions:

    Output 1

    Output 2

    problemfun1<-function(n){
      if(n<1) return(1)
      problemfun1(n-1)
      print(n)
    }

    problemfun1<-function(n){
      if(n<1) return(1)
      print(n)
      problemfun1(n-1)
    }

  4. Write a recursive algorithm to evaluate the Fibonacci sequence. (In a Fibonacci sequence, each item is the sum of the previous two.)

  5. Write a function to invert the values in a stack.

  6. Write a function to implement two stacks using only one array. The routines should not indicate an overflow unless every cell in the array is filled.

  7. Create a data structure which...