HW-2

PROJECT220921/src/Lab3Ex02.java

@@ -0,0 +1,18 @@
+public class Lab3Ex02 {
+    public static void main(String[] args) {
+        int[][] n = new int[][] {
+                { 1 },
+                { 1, 2, 3 },
+                { 1 },
+                { 1, 2, 3, 4 },
+                { 1, 2 }
+        };
+
+        for (int i = 0; i < n.length; ++i) {
+            for (int j : n[i]) {
+                System.out.print(j + " ");
+            }
+            System.out.println();
+        }
+    }
+}

PROJECT220921/src/Lab3Ex04.java

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+import java.util.Scanner;
+
+public class Lab3Ex04 {
+    public static void main(String[] args) {
+        System.out.print("소문자 알파벳 하나를 입력하세요.");
+        Scanner in = new Scanner(System.in);
+        String s = in.next();
+        char c = s.charAt(0);
+
+        for (char i = c; i >= 'a'; --i) {
+            for (char j = 'a'; j <= i; ++j) {
+                System.out.print(j);
+            }
+            System.out.println();
+        }
+    }
+}

PROJECT220921/src/Lab3Ex06.java

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+import java.util.Scanner;
+
+public class Lab3Ex06 {
+    public static void main(String[] args) {
+        System.out.print("금액을 입력하세요.");
+        Scanner in = new Scanner(System.in);
+        int price = in.nextInt();
+        int[] unit = { 50000, 10000, 1000, 500, 100, 50, 10, 1 };
+        int[] result = new int[8];
+
+        for (int i = 0; i < unit.length; ++i) {
+            result[i] = price / unit[i];
+            price = price % unit[i];
+            if (result[i] != 0) {
+                System.out.printf("%d원 짜리 : %d개%s", unit[i], result[i], System.lineSeparator());
+            }
+        }
+    }
+}

PROJECT220921/src/Lab3Ex08.java

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+import java.util.Arrays;
+import java.util.Scanner;
+
+public class Lab3Ex08 {
+    public static void main(String[] args) {
+        System.out.print("생성할 난수의 개수 : ");
+        Scanner in = new Scanner(System.in);
+        int num = in.nextInt();
+        int[] randNum = new int[100];
+        for (int i = 0; i < num; ++i) {
+            randNum[i] = (int)(Math.random() * 100);
+            while (isOverlap(i, randNum, randNum[i])) {
+                randNum[i] = (int)(Math.random() * 100);
+            }
+        }
+        printArrayToNum(randNum, num);
+    }
+
+    public static boolean isOverlap(int index, int[] arr, int num) {
+        for (int i = 0; i < index; ++i) {
+            if (arr[i] == num) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public static void printArrayToNum(int[] randNum, int num) {
+        for (int i = 0; i < num; ++i) {
+            if (i % 5 == 0) {
+                System.out.println();
+            }
+            System.out.print(randNum[i] + " ");
+        }
+    }
+}

PROJECT220921/src/Lab3Ex10.java

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+public class Lab3Ex10 {
+    public static void main(String[] args) {
+        int[][] arr = new int[4][4];
+        for (int i = 0; i < 10; ++i) {
+            int randNum = (int)(Math.random() * 10);
+            int x = 0;
+            int y = 0;
+            while (arr[x][y] != 0) {
+                x = (int)((Math.random() * 10) % 4);
+                y = (int)((Math.random() * 10) % 4);
+            }
+            arr[x][y] = randNum;
+        }
+
+        for (int i = 0; i < 4; ++i) {
+            for (int j = 0; j < 4; ++j) {
+                System.out.print(arr[i][j] + " ");
+            }
+            System.out.println();
+        }
+    }
+}

PROJECT220921/src/Lab3Ex12.java

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+import java.util.Scanner;
+
+public class Lab3Ex12 {
+    public static void main(String[] args) {
+        double sum = 0.0f;
+        for (int i = 0; i < args.length; ++i) {
+            try {
+                sum += Integer.valueOf(args[i]);
+            } catch (NumberFormatException e) {
+                sum += 0.0f;
+            }
+        }
+        System.out.println("합 = " + sum);
+    }
+}

PROJECT220921/src/Lab3Ex14.java

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+import java.util.Scanner;
+
+public class Lab3Ex14 {
+    public static void main(String[] args) {
+        String course[]  = { "Java", "C++", "HTML5", "컴퓨터구조", "네트워크" };
+        int score[] = {87, 88, 79, 98, 79 };
+        Scanner in = new Scanner(System.in);
+        while (true) {
+            System.out.print("과목 이름>> ");
+            String courseName = in.next();
+            if (courseName.equals("그만")) {
+                break;
+            } else {
+                for (int i = 0; i < course.length; ++i) {
+                    if (courseName.equals(course[i])) {
+                        System.out.printf("%s의 점수는 %d\n", course[i], score[i]);
+                    }
+                }
+            }
+
+        }
+    }
+}