finished exercise 38

Author: Jonathan-Birkey

src/com/github/jonathanbirkey/chapter05/Exercise37.java

@@ -18,25 +18,25 @@ public static void main(String[] args) {
     input.close();
 
     int count = 0;
-    int binary = 0;
+    int binaryNum = 0;
 
     while (decimal > 0) {
       if (decimal % 2 == 0) {
-        binary += 0;
+        binaryNum += 0;
       } else {
-        binary += 1;
+        binaryNum += 1;
       }
       decimal = decimal / 2;
       if (decimal > 0) {
-        binary = binary * 10;
+        binaryNum = binaryNum * 10;
       }
 
       count++;
     }
 
     for (int i = 0; i < count; i++) {
-      System.out.printf("%d", binary % 10);
-      binary = binary / 10;
+      System.out.printf("%d", binaryNum % 10);
+      binaryNum = binaryNum / 10;
     }
   }
 }

src/com/github/jonathanbirkey/chapter05/Exercise38.java

@@ -2,14 +2,39 @@
  * @author : Jonathan Birkey
  * @mailto : [email protected]
  * @created : 28Feb2024
- *     <p>(Display leap years) Write a program that displays all the leap years, 10 per line, from
- *     101 to 2100, separated by exactly one space. Also display the number of leap years in this
- *     period.
+ *     <p>(Decimal to octal) Write a program that prompts the user to enter a decimal integer and
+ *     displays its corresponding octal value. Don’t use Java’s Integer.toOctalString(int) in this
+ *     program.
  */
 package com.github.jonathanbirkey.chapter05;
 
+import java.util.Scanner;
+
 public class Exercise38 {
   public static void main(String[] args) {
-    // TODO: solve
+    Scanner input = new Scanner(System.in);
+    System.out.print("Enter a decimal integer: ");
+    int decimal = input.nextInt();
+    input.close();
+
+    int count = 0;
+    int octalNum = 0;
+
+    while (decimal > 0) {
+      octalNum += decimal % 8;
+      decimal = decimal / 8;
+      if (decimal > 0) {
+        octalNum = octalNum * 10;
+      }
+
+      count++;
+    }
+
+    // 127 = 177
+    // 127 ÷ 8 = 15(Quotient) and (7)Remainder
+    for (int i = 0; i < count; i++) {
+      System.out.printf("%d", octalNum % 10);
+      octalNum = octalNum / 10;
+    }
   }
 }