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tfylee98tfylee98
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ch10
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Lines changed: 160 additions & 137 deletions

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‎ch10/Big.java‎

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import java.math.BigInteger;
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/**
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* calculating factorial with BigInteger
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*/
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public class Big {
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public static BigInteger factorial(int n) {
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BigInteger factorial = BigInteger.valueOf(n);
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for (int i = 1; i < n; i++) {
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BigInteger mult = BigInteger.valueOf(i);
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factorial = factorial.multiply(mult);
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}
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return factorial;
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}
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public static void main(String[] args) {
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for (int i = 0; i < 31; i++) {
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System.out.println(i + "\t" + factorial(i));
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}
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}
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}

‎ch10/PointRect.java‎

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import java.awt.Point;
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import java.awt.Rectangle;
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/**
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* Demonstates use of Point and Rectangle classes.
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*/
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public class PointRect {
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public static void main(String[] args) {
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Point blank;
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blank = new Point(3, 4);
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System.out.println(blank);
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int x = blank.x;
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System.out.println(blank.x + ", " + blank.y);
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int sum = blank.x * blank.x + blank.y * blank.y;
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Rectangle box = new Rectangle(0, 0, 100, 200);
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moveRect(box, 50, 100);
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System.out.println(box);
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box.translate(50, 100);
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Rectangle box1 = new Rectangle(0, 0, 100, 200);
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Rectangle box2 = box1;
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System.out.println(box2.width);
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box1.grow(50, 50);
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System.out.println(box2.width);
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}
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/**
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* Prints the attributes of a Point object.
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*/
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public static void printPoint(Point p) {
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System.out.println("(" + p.x + ", " + p.y + ")");
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}
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/**
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* Computes the distance between two points.
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*/
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public static double distance(Point p1, Point p2) {
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int dx = p2.x - p1.x;
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int dy = p2.y - p1.y;
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return Math.sqrt(dx * dx + dy * dy);
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}
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/**
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* Finds the center of a Rectangle and returns a new Point.
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*/
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public static Point findCenter(Rectangle box) {
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int x = box.x + box.width / 2;
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int y = box.y + box.height / 2;
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return new Point(x, y);
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}
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/**
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* Moves a Rectangle by modifying the x and y attributes.
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*/
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public static void moveRect(Rectangle box, int dx, int dy) {
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box.x = box.x + dx;
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box.y = box.y + dy;
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}
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/**
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* Exercise on returning objects.
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*/
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public static void exercise2() {
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Point blank = new Point(5, 8);
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Rectangle rect = new Rectangle(0, 2, 4, 4);
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Point center = findCenter(rect);
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double dist = distance(center, blank);
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System.out.println(dist);
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}
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/**
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* Exercise on aliasing.
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*/
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public static void exercise3() {
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Rectangle box1 = new Rectangle(2, 4, 7, 9);
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Point p1 = findCenter(box1);
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printPoint(p1);
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box1.grow(1, 1);
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Point p2 = findCenter(box1);
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printPoint(p2);
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}
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}
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import java.awt.Point;
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import java.awt.Rectangle;
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/**
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* Demonstates use of Point and Rectangle classes.
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*/
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public class PointRect {
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public static void main(String[] args) {
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Point blank;
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blank = new Point(3, 4);
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System.out.println(blank);
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int x = blank.x;
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System.out.println(blank.x + ", " + blank.y);
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int sum = blank.x * blank.x + blank.y * blank.y;
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Rectangle box = new Rectangle(0, 0, 100, 200);
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moveRect(box, 50, 100);
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System.out.println(box);
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box.translate(50, 100);
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Rectangle box1 = new Rectangle(0, 0, 100, 200);
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Rectangle box2 = box1;
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System.out.println(box2.width);
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box1.grow(50, 50);
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System.out.println(box2.width);
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}
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/**
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* Prints the attributes of a Point object.
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*/
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public static void printPoint(Point p) {
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System.out.println("(" + p.x + ", " + p.y + ")");
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}
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/**
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* Computes the distance between two points.
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*/
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public static double distance(Point p1, Point p2) {
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int dx = p2.x - p1.x;
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int dy = p2.y - p1.y;
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return Math.sqrt(dx * dx + dy * dy);
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}
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/**
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* Finds the center of a Rectangle and returns a new Point.
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*/
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public static Point findCenter(Rectangle box) {
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int x = box.x + box.width / 2;
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int y = box.y + box.height / 2;
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return new Point(x, y);
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}
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/**
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* Moves a Rectangle by modifying the x and y attributes.
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*/
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public static void moveRect(Rectangle box, int dx, int dy) {
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box.x = box.x + dx;
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box.y = box.y + dy;
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}
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/**
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* Exercise on returning objects.
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*/
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public static void exercise2() {
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Point blank = new Point(5, 8);
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Rectangle rect = new Rectangle(0, 2, 4, 4);
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Point center = findCenter(rect);
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double dist = distance(center, blank);
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System.out.println(dist);
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}
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/**
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* Exercise on aliasing.
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*/
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public static void exercise3() {
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Rectangle box1 = new Rectangle(2, 4, 7, 9);
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Point p1 = findCenter(box1);
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printPoint(p1);
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box1.grow(1, 1);
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Point p2 = findCenter(box1);
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printPoint(p2);
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}
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}

‎ch10/Pow.java‎

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/**
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* BigInteger exercise.
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*/
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public class Pow {
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/**
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* Integer exponentiation.
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*/
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public static int pow(int x, int n) {
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if (n == 0) return 1;
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// find x to the n/2 recursively
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int t = pow(x, n / 2);
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// if n is even, the result is t squared
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// if n is odd, the result is t squared times x
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if (n % 2 == 0) {
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return t * t;
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} else {
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return t * t * x;
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}
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}
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}
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import java.math.BigInteger;
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/**
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* BigInteger exercise.
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*/
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public class Pow {
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/**
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* Integer exponentiation.
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*/
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public static BigInteger pow(int x, int n) {
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if (n == 0) return BigInteger.valueOf(1);
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// find x to the n/2 recursively
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BigInteger t = pow(x, n / 2);
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// if n is even, the result is t squared
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// if n is odd, the result is t squared times x
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if (n % 2 == 0) {
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return t.multiply(t);
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} else {
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return t.multiply(t).multiply(BigInteger.valueOf(x));
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}
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}
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}

‎ch10/Riddle.java‎

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import java.awt.Point;
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/**
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* Exercise on passing objects as parameters.
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*/
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public class Riddle {
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public static int riddle(int x, Point p) {
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x = x + 7;
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return x + p.x + p.y;
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}
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public static void main(String[] args) {
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int x = 5;
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Point blank = new Point(1, 2);
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System.out.println(riddle(x, blank));
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System.out.println(x);
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System.out.println(blank.x);
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System.out.println(blank.y);
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}
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}
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import java.awt.Point;
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/**
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* Exercise on passing objects as parameters.
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*/
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public class Riddle {
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public static int riddle(int x, Point p) {
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x = x + 7;
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return x + p.x + p.y;
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}
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public static void main(String[] args) {
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int x = 5;
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Point blank = new Point(1, 2);
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System.out.println(riddle(x, blank));
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System.out.println(x);
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System.out.println(blank.x);
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System.out.println(blank.y);
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}
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}

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