4.   Algorithms and Data Structures


In this chapter we describe and implement some of the most important algorithms and data structures in use on computers today. (For a more in-depth treatment, we recommend the companion textbook Algorithms, 4th Edition.) We begin by considering a powerful framework for measuring and analyzing the efficiency of our programs. This enables us to compare algorithms and accurately predict performance. Next, we consider several novel algorithms for the classic problem of sorting. Then, we build the most important higher level data structures, including stacks, queues, and symbol tables.

Java programs in this chapter.

Below is a list of Java programs in this chapter. Click on the program name to access the Java code; click on the reference number for a brief description; read the textbook for a full discussion.

4.1.1 ThreeSum.java 3-sum problem
4.1.2 DoublingTest.java validating a doubling hypothesis
4.2.1 Questions.java binary search (20 questions)
4.2.2 Gaussian.java bisection search
4.2.3 BinarySearch.java binary search (in a sorted array)
4.2.4 Insertion.java insertion sort
4.2.5 InsertionTest.java doubling test for insertion sort
4.2.6 Merge.java mergesort
4.2.7 FrequencyCount.java frequency counts
4.3.1 ArrayStackOfStrings.java stack of strings (array)
4.3.2 LinkedStackOfStrings.java stack of strings (linked list)
4.3.3 ResizingArrayStackOfStrings.java stack of strings (resizing array)
4.3.4 Stack.java generic stack
4.3.5 Evaluate.java expression evaluation
4.3.6 Queue.java generic queue
4.3.7 MM1Queue.java M/M/1 queue simulation
4.3.8 LoadBalance.java load balancing simulation
4.4.1 Lookup.java dictionary lookup
4.4.2 Index.java indexing
4.4.3 HashST.java hash table
4.4.4 BST.java binary search tree
4.4.5 DeDup.java dedup filter
4.5.1 Graph.java graph data type
4.5.2 IndexGraph.java using a graph to invert an index
4.5.3 PathFinder.java shortest-paths client
4.5.4 PathFinder.java shortest-paths implementation
4.5.5 SmallWorld.java small-world test
4.5.6 Performer.java performer–performer graph