cs106A-MIT-过滤掉了图形部分

作者: 暗黑破坏球嘿哈 | 来源:发表于2017-03-30 07:54 被阅读76次

content from MIT-cs106A
枚举，接口，搜索算法，标准库
课程内容：163

/**
 * The Student class keeps track of the following pieces of data
 * about a student: the student's name, ID number, and the number
 * of credits the student has earned toward graduation.
 * All of this information is entirely private to the class.
 * Clients can obtain this information only by using the various
 * methods defined by the class.
 */

public class Student {
    
    /* Public constants */

    /** The number of units required for graduation */
    public static final double UNITS_TO_GRADUATE = 180.0;


    /**
     * Creates a new Student object with the specified name and ID.
     * @param studentName The student's name as a String
     * @param studentID The student's ID number as an int
     */
    public Student(String studentName, int studentID) {
        name = studentName;
        ID = studentID;
    }

    /**
     * Gets the name of this student.
     * @return The name of this student
     */
    public String getName() {
        return name;
    }

    /**
     * Gets the ID number of this student.
     * @return The ID number of this student
     */
    public int getID() {
        return ID;
    }

    /**
     * Sets the number of units earned.
     * @param units The new number of units earned
     */
    public void setUnits(double units) {
        unitsEarned = units;
    }

    /**
     * Gets the number of units earned.
     * @return The number of units this student has earned
     */
    public double getUnits() {
        return unitsEarned;
    }

    /**
     * Increments the number of units earned.
     * @param additionalUnits The additional number of units earned
     */
    public void incrementUnits(double additionalUnits) {
        unitsEarned += additionalUnits;
    }
    
    /**
     * Gets the number of units earned.
     * @return Whether the student has enough units to graduate
     */
    public boolean hasEnoughUnits() {
        return (unitsEarned >= UNITS_TO_GRADUATE);
    }
    
    
    /**
     * Creates a string identifying this student.
     * @return The string used to display this student
     */
    public String toString() {
        return name + " (#" + ID + ")";
    }


    /* Private instance variables */
    private String name;        /* The student's name         */
    private int ID;             /* The student's ID number    */
    private double unitsEarned; /* The number of units earned */

}

/**
 * File: Stanford.java
 * -------------------
 * The program provides an example of using Student objects
 */

import acm.program.*;

public class Stanford extends ConsoleProgram {
    
    /* Constants */
    private static final int CS106A_UNITS = 5;
    
    public void run() {
        setFont("Times New Roman-28");
                
        Student mehran = new Student("Mehran Sahami", 38000000);
        mehran.setUnits(3);
        printUnits(mehran);

        Student nick = new Student("Nick Troccoli", 57000000);
        nick.setUnits(179);
        printUnits(nick);
        
        println("Called tryToAddUnits to add to Nick's units...");
        tryToAddUnits(nick.getUnits(), CS106A_UNITS);
        printUnits(nick);
                
        takeCS106A(mehran);
        takeCS106A(nick);
        
        printUnits(mehran);
        printUnits(nick);
    }
    
    /**
     * Prints the name and number of units that student s has,
     * as well as whether the student can graduate
     * @param s The student who we will print information for
     */
    private void printUnits(Student s) {
        println(s.getName() + " has " + s.getUnits() + " units");
        println(s.toString() + " can graduate: " + s.hasEnoughUnits());
    }
    
    /**
     * BUGGY!! -- Tries to add to numUnits, but only adds to copy!
     * @param numUnits Original number of units
     * @param numUnitsToAdd Number of units to add to original
     */
    private void tryToAddUnits(double numUnits, double numUnitsToAdd) {
        numUnits += numUnitsToAdd;
    }

    /**
     * States that student s takes CS106A and increments number of units
     * @param s The student who will be taking CS106A
     */
    private void takeCS106A(Student s) {
        println(s.getName() + " takes CS106A!!");
        s.incrementUnits(CS106A_UNITS);
    }
}

file reading

file reading example

file reading code for example

/* 
 * FilesExample.java
 * -----------------
 * This program shows an example of reading a file.
 */

/* 
line==null can be put in while()
String line = rd.readLine();
while(line!=null) println();
 */

import acm.program.*;
import acm.util.*;
import java.io.*;

public class FilesExamples extends ConsoleProgram {
    
    public void run() {
        setFont("Times New Roman-24");
        
        try {
            BufferedReader rd = new BufferedReader(new FileReader("claire.txt"));
            while (true) {
                String line = rd.readLine();
                if (line == null) break;
                println("Read line: [" + line + "]");
            }
            rd.close();
            
        } catch (IOException ex) {
            throw new ErrorException(ex);
        }
   
    }
    
}

/* 
 * AnotherFileExample.java
 * -----------------------
 * This program shows an example of reading a file.
 */

/*
open or create file in a method, two try-catch, convenient for debugging
*/

import acm.program.*;
import acm.util.*;
import java.io.*;

public class AnotherFileExample extends ConsoleProgram {
    
    public void run() {
        setFont("Times New Roman-24");
        
        BufferedReader rd = openFile("Please enter filename: ");
        
        try {   
            while (true) {
                String line = rd.readLine();
                if (line == null) break;
                println("Read line: [" + line + "]");
            }
            rd.close();
        } catch (IOException ex) {
            throw new ErrorException(ex);
        }   
        
    }

    private BufferedReader openFile(String prompt) {
        BufferedReader rd = null;
        
        while (rd == null) {
            try {
                String filename = readLine(prompt);
                rd = new BufferedReader(new FileReader(filename));
            } catch (IOException ex) {
                println("Can't open that file, chief.");
            }
        }
        return rd;
    }
    
    
}

/* 
 * CopyFile.java
 * -------------
 * This program shows an example of copying a text file
 * line by line.
 */

import acm.program.*;
import acm.util.*;
import java.io.*;

public class CopyFile extends ConsoleProgram {
    
    public void run() {
        setFont("Times New Roman-24");
        BufferedReader rd = openFile("Please enter filename: ");
        
        try {
            PrintWriter wr = new PrintWriter(new FileWriter("copy.txt"));
            
            while (true) {
                String line = rd.readLine();
                if (line == null) break;
                println(line);  // console
                wr.println(line);  // file
            }
            
            rd.close();
            wr.close();
            
        } catch (IOException ex) {
            throw new ErrorException(ex);
        }           
    }

    private BufferedReader openFile(String prompt) {
        BufferedReader rd = null;
        
        while (rd == null) {
            try {
                String filename = readLine(prompt);
                rd = new BufferedReader(new FileReader(filename));
            } catch (IOException ex) {
                println("Nice try punk.  That file doesn't exist.");
            }
        }
        return rd;
    }
    
    
}

/* 
 * SimpleArrayListExample.java
 * ---------------------------
 * This program shows an example of using an ArrayList.
 */

import acm.program.*;
import java.util.*;

public class SimpleArrayListExample extends ConsoleProgram {
    
    
    public void run() {
           setFont("Courier New-bold-24");

           ArrayList<String> strList = new ArrayList<String>();
           readStringList(strList);
           printArrayList(strList);
        
        ArrayList<Integer> intList = new ArrayList<Integer>();
            readIntList(intList);
        printArrayList(intList);
    }
    
    private void readStringList(ArrayList<String> list) {
        while (true) {
            String line = readLine("Next line: ");
            if (line.equals("")) break;
            list.add(line);
        }
    }
    
    private void printArrayList(ArrayList list) {
        println("List contains "  + list.size() + " elements");
        for(int i = 0; i < list.size(); i++) {
            println(list.get(i));   // unboxes value if needed (e.g., int)
        }
    }

    private void readIntList(ArrayList<Integer> list) {
        while (true) {
            int value = readInt("Next integer (-1 to stop): ");
            if (value == -1) break;
            list.add(value);    // boxes value (int) to Integer
        }
    }


}

/* 
 * IntegerArrayListExample.java
 * ---------------------------
 * This program shows an example of using an Integer ArrayList.
 */

import acm.program.*;
import java.util.*;

public class IntegerArrayListExample extends ConsoleProgram {
    
    public void run() {
               setFont("Courier New-bold-24");

               ArrayList<Integer> intList = new ArrayList<Integer>();
            readList(intList);
        printArrayList(intList);
        
            readList(intList);
        printArrayList(intList);
    }
    
    private void readList(ArrayList<Integer> list) {
        while (true) {
            int value = readInt("Next number: ");
            if (value == -1) break;
            list.add(value);    // boxes value (int) to Integer
        }
    }
    
    private void printArrayList(ArrayList list) {
        println("List contains "  + list.size() + " elements");
        for(int i = 0; i < list.size(); i++) {
            println(list.get(i));  // unboxes Integer to int
        }
    }

}

/* 
 * File: AverageScores.java
 * ------------------------
 * This program shows an example of using arrays.
 */

import acm.program.*;

public class AverageScores extends ConsoleProgram {
    
    private static final int SENTINEL = -1;
    private static final int MAX_SCORES = 1000; // actual size
    
    public void run() {
        setFont("Courier New-bold-24");

        int[] midtermScores = new int[MAX_SCORES];
        int numScores = 0;              // effective size
        
        while (true) {
        int score = readInt("Score: ");
        if (score == SENTINEL) break;
        midtermScores[numScores++] = score;
    }
        
        double averageScore = computeAverage(midtermScores, numScores);
        
        println("Average score: " + averageScore);
    }

    private double computeAverage(int[] arr, int numScores) {
        double average = 0;
        for(int i = 0; i < numScores; i++) {
            average += arr[i];
        }
        average = average / numScores;
        return average;
    }
    
}

/* 
 * SwapExample.java
 * -----------------
 * This program shows an example of using arrays when swapping values.
 */

import acm.program.*;

public class SwapExample extends ConsoleProgram {
        
    public void run() {
        setFont("Courier New-bold-24");

        int[] array = new int[5];
        array[0] = 1;
        array[1] = 2;
        
        println("Buggy swap results:");
        swapElementsBuggy(array[0], array[1]);
        println("array[0] = " + array[0]);
        println("array[1] = " + array[1]);
        
        println("Happy swap results:");
        swapElementsHappy(array, 0, 1);
        println("array[0] = " + array[0]);
        println("array[1] = " + array[1]);
    }

    private void swapElementsBuggy(int x, int y) {
        int temp = x;
        x = y;
        y = temp;
    }
    
    private void swapElementsHappy(int[] arr, int pos1, int pos2) {
        int temp = arr[pos1];
        arr[pos1] = arr[pos2];
        arr[pos2] = temp;
    }
    
}

/* 
 * File: TwoDimensionalArrayExample.java
 * -------------------------------------
 * This program shows an example of using 2-dimensional arrays.
 */

import acm.program.*;

public class TwoDimensionalArrayExample extends ConsoleProgram {
 
    public static final int ROWS = 2;
    public static final int COLS = 3;
    
    public void run() {
            setFont("Courier New-bold-24");

        int[][] arr = new int[ROWS][COLS];
        initMatrix(arr);
        printMatrix(arr);
    }

    private void initMatrix(int[][] matrix) {
        for(int i = 0; i < matrix.length; i++) {
            for(int j = 0; j < matrix[0].length; j++) {
                matrix[i][j] = j;
            }
        }
    }
    
    private void printMatrix(int[][] matrix) {
        for(int i = 0; i < matrix.length; i++) {
            for(int j = 0; j < matrix[0].length; j++) {
                print(matrix[i][j] + " ");
            }
            println();
        }
    }
 
    
}

import acm.program.*;


public class TestScores extends ConsoleProgram {

    // Maximum number of students in a course
    private static final int MAX_STUDENTS = 1000;

    public void run() {
        setFont("Times New Roman-24");
        
        int numScores = readInt("Number of scores per student: ");
        scores = new int[MAX_STUDENTS][numScores];
        
        initScores();
        
        println("Scores[0] before increment");
        printList(scores[0]);

        incrementScoreList(scores[0]);
        println("Scores[0] after increment");
        printList(scores[0]);
    }

    // Initialized score grid to all be 0
    private void initScores() {
        for(int i = 0; i < scores.length; i++) {
            for(int j = 0; j < scores[0].length; j++) {
                scores[i][j] = 0;
            }
        }
    }
    
    // Prints every element of list on a separate line
    private void printList(int[] list) {
        for(int i = 0; i < list.length; i++) {
            println(list[i]);
        }
    }
    
    // Adds 1 to every element of list
    private void incrementScoreList(int[] list) {
        for(int i = 0; i < list.length; i++) {
            list[i]++;
        }
    }
    
    /* private instance variable */
    private int[][] scores;
}

/*
 * File: HashMapExample.java
 * -------------------------
 * This program shows an example of using a HashMap to keep
 * track of a simple phonebook (mapping names to phone numbers).
 */

import acm.program.*;
import java.util.*;

public class HashMapExample extends ConsoleProgram {
    
    public void run() {
        setFont("Times New Roman-24");
        
        println("Reading in phone numbers");
        readPhoneNumbers();

        println("Displaying phone numbers");
        displayAllNumbers();

        println("Looking up phone numbers");
        lookUpNumbers();
    }
    
    // Ask the user for phone numbers to store in phonebook.
    private void readPhoneNumbers() {
        while (true) {
            String name = readLine("Enter name: ");
            if (name.equals("")) break;
            int number = readInt("Phone number (as int): ");
            phonebook.put(name, number);
        }
    }
    
    // Print out all the names/phone numbers in the phonebook.
    // (This version of the method uses iterators.)
    private void displayAllNumbers() {
        Iterator<String> it = phonebook.keySet().iterator();
        while (it.hasNext()) {
            String name = it.next();
            Integer number = phonebook.get(name);
            println(name + ": " + number);
        }
    }

    // Print out all the names/phone numbers in the phonebook.
    // (This version of the method uses a foreach loop.)
    private void displayAllNumbers2() {
        for(String name : phonebook.keySet()) {
            Integer number = phonebook.get(name);
            println(name + ": " + number);
        }
    }
    
    // Allow the user to lookup phone numbers in the phonebook
    // by looking up the number associated with a name.
    private void lookUpNumbers() {
        while (true) {
            String name = readLine("Enter name to lookup: ");
            if (name.equals("")) break;
            Integer number = phonebook.get(name);
            if (number == null) {
                println(name + " not in phonebook");
            } else {
                println(number);
            }
        }
    }


    /* Private instance variable */
    private Map<String,Integer> phonebook = new HashMap<String,Integer>();
}