abstract class PairMap {
protected String keyArray[];
protected String valueArray[];
abstract String get(String key);
abstract void put(String key, String value);
abstract String delete(String key);
abstract int length();
}
class Dictionary extends PairMap {
private int size;
private int n = 0;
public Dictionary(int size) {
this.size = size;
keyArray = new String[size];
valueArray = new String[size];
}
String get(String key) {
for (int i = 1; i <= n; i++) {
if (keyArray[i].equals(key)) {
return valueArray[i];
}
}
return null;
}
void put(String key, String value) {
// 1. keyArray에 key가 있으면 기존 value 를 바꾼다
for (int i = 1; i <= n; i++) {
if (keyArray[i].equals(key)) {
valueArray[i] = value;
return;
}
}
// 2.기존에 keyArray에 key가 없을때 추가
n++;
keyArray[n] = key;
valueArray[n] = value;
}
String delete(String key) {
String value = null ;
for (int i = 1; i <= n; i++) {
if (keyArray[i].equals(key)) {
value=valueArray[i];
valueArray[i]=null;
break;
}
}
return value;
}
int length() {
return n;
}
}
class Main {
public static void main(String[] args) {
Dictionary dic = new Dictionary(10); v
dic.put("황기태", "자바");
dic.put("이재문", "c언어");
dic.put("이재문", "파이선");
System.out.println("이재문의 값은" + dic.get("황기태"));
System.out.println("황기태의 값은" + dic.get("이재문"));
dic.delete("황기태");
System.out.println("황기태의 값은" + dic.get("황기태"));
}
}*/
interface Shape{
final double PI = 3.14;
void draw();
double getArea();
default public void redraw() {
System.out.println("다시 그려");
draw();
}
}
class Circle implements Shape {
private int r;
Circle(int r){
this.r = r;
}
public void draw() {
System.out.println("반지름은"+r+"임");
}
public double getArea() {
return r*r*PI;
}
}
class Oval implements Shape{
private int a,b;
Oval(int a,int b){
this.a = a;
this.b = b;
}
public void draw() {
System.out.println(a+"x"+b+"타원");
}
public double getArea() {
return a*b*PI;
}
}
class Rect implements Shape{
private int c,d;
Rect(int c,int d){
this.c = c;
this.d = d;
}
public void draw() {
System.out.println(c+"x"+d+"사각");
}
public double getArea() {
return c*d;
}
}
class Main{
public static void main(String[] args) {
Shape donut = new Circle(10);
Shape donu = new Oval(20,30);
Shape don = new Rect(10, 40);
donut.redraw();
donu.redraw();
don.redraw();
System.out.println("면"+donut.getArea());
System.out.println("men"+donu.getArea());
System.out.println("men"+don.getArea());
}
}