#7. 2주차 과제 3 [Chap03_3C-1 ~ 3-8]

3C-1. (ID_Tester)

 

package practice;
 
class ID{
    /*싱글톤?*/
    private static int counter = 0;
    private int id;
    
    public ID() {    id = ++counter;    }
    public int getId() {    return id;        }
    
    public static int getCounter() {    return counter;        }
        
    
}
public class ID_Tester_3C_1 {
    public static void main(String[] args) {
        ID a = new ID();
        ID b = new ID();
        
        System.out.println("a의 아이디: "+a.getId());
        System.out.println("b의 아이디: "+b.getId());
        
        System.out.println("부여한 아이디 개수: "+ID.getCounter());
        
    }
}
 

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3-6. (StringBinarySearch)

package practice;
 
import java.util.Arrays;
import java.util.Scanner;
 
public class StringBinarySearch_3_6 {
    public static void main(String[] args) {
        Scanner stdIn = new Scanner(System.in);
        
        String[] x = {
                "abstract",    "assert",    "boolean",    "break",     "byte",
                "case",        "catch",    "char",        "class",     "const",
                "continue",    "default",    "do",        "double",     "else",
                "enum",        "extends",    "final",    "finally",     "float",
                "for",        "goto",        "if",        "implements","import",
                "instanceof","int",        "interface","long",         "native",
                "new",        "package",    "private",    "protected", "public",
                "return",    "short",    "static",    "strictfp",     "super",
                "switch",    "syncronized", "this",    "throw",     "throws",
                "transient","try",        "void",        "volatile",     "while"
        };
        
        System.out.print("원하는 키워드를 입력하세요: ");
        String ky = stdIn.next();
        
        int idx = Arrays.binarySearch(x, ky);
        
        if(idx<0)
            System.out.println("해당 키워드가 없습니다.");
        else
            System.out.println("해당 키워드를 x["+idx+"]에 있습니다.");
    }
}
 

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3C-2. (A)

package practice;
 
public class A_3C_2 implements Comparable<A_3C_2> {
    
    /*
     * 객체를 정렬하는 Comparable
     */
    
    @Override
    public int compareTo(A_3C_2 c) {
        /*
         * this가 c보다 크면 양의 값 반환
         * this가 c보다 작으면 음의 값 반환
         * this와 c와 같으면 0반환
         */
        
        return 0;
    }
    
    @Override
    public boolean equals(Object obj) {
        /*
         * this와 c와 같으면 true 반환
         * 같지않으면 false 반환
         */
        return super.equals(obj);
    }
    
 
}
 
 

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3-7. (X)

package practice;
 
import java.util.Comparator;
 
class X{
    public static final Comarator<T> COMPARATOR = new  Comp_3_7();
 
    private static class Comp_3_7 implements Comparator<T>{
        @Override
        public int compare(T d1, T d2) {
            //d1이 d2보다 크면 양의 값 반환
            //d1이 d2보다 작으면 음의 값 반환
            //d1이 s2와 같으면 0반환
            return 0;
        }
 
    }
}
 

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3-8. (PhysExamSearch)

package practice;
 
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;
 
public class PhysExamSearch_3_8 {
    
    static class PhyscData{
        private String name;
        private int height;
        private double vision;
        
 
        public PhyscData(String name, int height, double vision) {            
            this.name = name;
            this.height = height;
            this.vision = vision;
        }
        
        @Override
        public String toString() {
            return name +" "+height+" "+vision;
        }
        
        public static final Comparator<PhyscData> HEIGHT_ORDER = 
                new HeightOrderComparator();
        
        
        private static class HeightOrderComparator implements Comparator<PhyscData>{
            @Override
            public int compare(PhyscData d1, PhyscData d2) {
                    return (d1.height > d2.height) ? 1 : 
                            (d1.height < d2.height) ? -1 : 0;
            }
        }    
    }
    
    public static void main(String[] args) {
        
        Scanner stdIn = new Scanner(System.in);
        PhyscData[]x = {
                new PhyscData("이나령",162,0.3),
                new PhyscData("유지훈", 168,0.4),
                new PhyscData("김한결",169,0.8),
                new PhyscData("홍준기",171,1.5),
                new PhyscData("전서현",173,0.7),
                new PhyscData("이호연",174,1.2),
                new PhyscData("이수민",175,2.0)
                
        };
        
        System.out.print("몇 cm인 사람을 찾고 있나요?: ");
        
        int height = stdIn.nextInt();
        int idx = Arrays.binarySearch(x, 
                new PhyscData("",height, 0.0),
                PhyscData.HEIGHT_ORDER);
        
        
        
        if(idx<0)
            System.out.println("요소가 없습니다.");
        else {
            System.out.println("x["+idx+"]에 있습니다.");
            System.out.println("찾은 데이터: "+x[idx]);
        }
    }
}
 

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3챕터 끝!!!!!!!