Java Code
Java programming environment. Here are instructions for setting up an IntelliJ-based Java programming environment for macOS, Windows, and Linux.
Standard libraries.
Here are the standard input and output libraries that we use throughout the textbook.
Programs in the textbook.
Below is a table of the Java programs in the textbook. 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. You can download all of the programs as introcs.jar and the data as introcs-data.zip; you can also download all of the programs and data as the IntelliJ project IntroCS.zip.
| 1 | ELEMENTS OF PROGRAMMING | |
|---|---|---|
| 1.1.1 | HelloWorld.java | Hello, World |
| 1.1.2 | UseArgument.java | using a command-line argument |
| 1.2.1 | Ruler.java | string concatenation example |
| 1.2.2 | IntOps.java | integer multiplication and division |
| 1.2.3 | Quadratic.java | quadratic formula |
| 1.2.4 | LeapYear.java | leap year |
| 1.2.5 | RandomInt.java | casting to get a random integer |
| 1.3.1 | Flip.java | flippling a fair coin |
| 1.3.2 | TenHellos.java | your first while loop |
| 1.3.3 | PowersOfTwo.java | computing powers of 2 |
| 1.3.4 | DivisorPattern.java | your first nested loops |
| 1.3.5 | HarmonicNumber.java | harmonic numbers |
| 1.3.6 | Sqrt.java | Newton's method |
| 1.3.7 | Binary.java | converting to binary |
| 1.3.8 | Gambler.java | gambler's ruin simulation |
| 1.3.9 | Factors.java | factoring integers |
| 1.4.1 | Sample.java | sampling without replacement |
| 1.4.2 | CouponCollector.java | coupon collector simulation |
| 1.4.3 | PrimeSieve.java | sieve of Eratosthenes |
| 1.4.4 | SelfAvoidingWalk.java | self-avoiding random walks |
| 1.5.1 | RandomSeq.java | generating a random sequence |
| 1.5.2 | TwentyQuestions.java | interactive user input |
| 1.5.3 | Average.java | averaging a stream of numbers |
| 1.5.4 | RangeFilter.java | a simple filter |
| 1.5.5 | PlotFilter.java | standard input-to-drawing filter |
| 1.5.6 | BouncingBall.java | bouncing ball |
| 1.5.7 | PlayThatTune.java | digital signal processing |
| 1.6.1 | Transition.java | computing the transition matrix |
| 1.6.2 | RandomSurfer.java | simulating a random surfer |
| 1.6.3 | Markov.java | mixing a Markov chain |
| 2 | FUNCTIONS | |
| 2.1.1 | Harmonic.java | harmonic numbers (revisited) |
| 2.1.2 | Gaussian.java | Gaussian functions |
| 2.1.3 | Coupon.java | coupon collector (revisited) |
| 2.1.4 | PlayThatTuneDeluxe.java | play that tune (revisited) |
| 2.2.1 | StdRandom.java | random number library |
| 2.2.2 | StdArrayIO.java | array I/O library |
| 2.2.3 | IFS.java | iterated function systems |
| 2.2.4 | StdStats.java | data analysis library |
| 2.2.5 | StdStats.java | data analysis library |
| 2.2.6 | Bernoulli.java | Bernoulli trials |
| 2.3.1 | Euclid.java | Euclid's algorithm |
| 2.3.2 | TowersOfHanoi.java | towers of Hanoi |
| 2.3.3 | Beckett.java | Gray code |
| 2.3.4 | Htree.java | recursive graphics |
| 2.3.5 | Brownian.java | Brownian bridge |
| 2.3.6 | LongestCommonSubsequence.java | longest common subsequence |
| 2.4.1 | Percolation.java | percolation scaffolding |
| 2.4.2 | VerticalPercolation.java | vertical percolation |
| 2.4.3 | PercolationVisualizer.java | percolation visualization client |
| 2.4.4 | PercolationProbability.java | percolation probability estimate |
| 2.4.5 | Percolation.java | percolation detection |
| 2.4.6 | PercolationPlot.java | adaptive plot client |
| 3 | OBJECT ORIENTED PROGRAMMING | |
| 3.1.1 | PotentialGene.java | identifying a potential gene |
| 3.1.2 | AlbersSquares.java | Albers squares |
| 3.1.3 | Luminance.java | luminance library |
| 3.1.4 | Grayscale.java | converting color to grayscale |
| 3.1.5 | Scale.java | image scaling |
| 3.1.6 | Fade.java | fade effect |
| 3.1.7 | Cat.java | concatenating files |
| 3.1.8 | StockQuote.java | screen scraping for stock quotes |
| 3.1.9 | Split.java | splitting a file |
| 3.2.1 | Charge.java | charged-particle data type |
| 3.2.2 | Stopwatch.java | stopwatch data type |
| 3.2.3 | Histogram.java | histogram data type |
| 3.2.4 | Turtle.java | turtle graphics data type |
| 3.2.5 | Spiral.java | spira mirabilis |
| 3.2.6 | Complex.java | complex number data type |
| 3.2.7 | Mandelbrot.java | Mandelbrot set |
| 3.2.8 | StockAccount.java | stock account data type |
| 3.3.1 | Complex.java | complex number data type (revisited) |
| 3.3.2 | Counter.java | counter data type |
| 3.3.3 | Vector.java | spatial vector data type |
| 3.3.4 | Sketch.java | document sketch data type |
| 3.3.5 | CompareDocuments.java | similarity detection |
| 3.4.1 | Body.java | gravitational body data type |
| 3.4.2 | Universe.java | n-body simulation |
| 4 | DATA STRUCTURES | |
| 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 |
| – | ST.java | symbol table data type |
| – | SET.java | set data type |
| 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 |
Exercise solutions.
Here is a list of solutions to selected coding exercises.
| 1 | ELEMENTS OF PROGRAMMING | |
|---|---|---|
| 1.1.1 | TenHelloWorlds.java | ten Hello, Worlds |
| 1.1.5 | UseThree.java | three command-line arguments |
| 1.2.20 | SumOfTwoDice.java | sum of two dice |
| 1.2.23 | SpringSeason.java | is month and day in Spring? |
| 1.2.25 | WindChill.java | compute wind chill factor |
| 1.2.26 | CartesianToPolar.java | Cartesian to polar coordinates |
| 1.2.29 | DayOfWeek.java | compute day of week from date |
| 1.2.30 | Stats5.java | average, min, max of 5 random numbers |
| 1.2.34 | ThreeSort.java | sort three integers |
| 1.2.35 | Dragon.java | dragon curve of order 5 |
| 1.3.8 | FivePerLine.java | print integers five per line |
| 1.3.11 | FunctionGrowth.java | table of functions |
| 1.3.12 | DigitReverser.java | reverse digits |
| 1.3.13 | Fibonacci.java | Fibonacci numbers |
| 1.3.15 | SeriesSum.java | convergent sum |
| 1.3.31 | Ramanujan.java | taxicab numbers |
| 1.3.32 | ISBN.java | ISBN checksum |
| 1.3.38 | Sin.java | sine function via Taylor series |
| 1.3.41 | MonteHall.java | Monte Hall problem |
| 1.4.2 | HugeArray.java | creating a huge array |
| 1.4.10 | Deal.java | deal poker hands |
| 1.4.13 | Transpose.java | tranpose a square matrix |
| 1.4.25 | InversePermutation.java | compute inverse permutation |
| 1.4.26 | Hadamard.java | compute Hadamard matrix |
| 1.4.30 | Minesweeper.java | create Minesweeper board |
| 1.4.33 | RandomWalkers.java | N random walkers |
| 1.4.35 | Birthdays.java | birthday problem |
| 1.4.37 | BinomialCoefficients.java | binomial coefficients |
| 1.5.1 | MaxMin.java | max and min from standard input |
| 1.5.3 | Stats.java | mean and stddev from standard input |
| 1.5.5 | LongestRun.java | longest consecutive run from stdin |
| 1.5.11 | WordCount.java | word count from standard input |
| 1.5.15 | Closest.java | closest point |
| 1.5.18 | Checkerboard.java | draw a checkerboard |
| 1.5.21 | Rose.java | draw a rose |
| 1.5.22 | Banner.java | animate a text banner |
| 1.5.31 | Spirograph.java | draw spirograph |
| 1.5.32 | Clock.java | animate a clock |
| 1.5.33 | Oscilloscope.java | simulate an oscilloscope |
| 2 | FUNCTIONS | |
| 2.1.4 | ArrayEquals.java | are two integer arrays equal? |
| 2.1.30 | BlackScholes.java | Black-Scholes option valuation |
| 2.1.32 | Horner.java | Horner's method to evaluate a polynomial |
| 2.1.33 | Benford.java | Benford's law |
| 2.1.38 | Calendar.java | create a calendar |
| 2.2.1 | Gaussian.java | overloaded gaussian distribution functions |
| 2.2.2 | Hyperbolic.java | hyperbolic trig functions |
| 2.2.4 | StdRandom.java | shuffle an array of doubles |
| 2.2.6 | StdArrayIO.java | array IO methods |
| 2.2.11 | Matrix.java | matrix operations |
| 2.2.12 | MarkovSquaring.java | page rank via matrix squaring |
| 2.2.14 | StdRandom.java | exponential random variable |
| 2.3.14 | AnimatedHtree.java | animated H-tree |
| 2.3.15 | IntegerToBinary.java | integer to binary conversion |
| 2.3.17 | Permutations.java | all permutations |
| 2.3.18 | PermutationsK.java | all permutations of size k |
| 2.3.19 | Combinations.java | all combinations |
| 2.3.20 | CombinationsK.java | all combinations of size k |
| 2.3.22 | RecursiveSquares.java | recursive squares |
| 2.3.24 | GrayCode.java | Gray code |
| 2.3.26 | AnimatedHanoi.java | animated Towers of Hanoi |
| 2.3.29 | Collatz.java | Collatz function |
| 2.3.30 | BrownianIsland.java | Brownian island |
| 2.3.31 | PlasmaCloud.java | plama cloud |
| 2.3.32 | McCarthy.java | McCarthy's 91 function |
| 2.3.33 | Tree.java | fractal tree |
| 2.4.15 | PercolationDirectedNonrecursive.java | directed percolation |