reviewed ch08

ChrisMayfield · ChrisMayfield · commit f484141b03fe · 2017-08-18T15:06:17.000-04:00
diff --git a/appe/Digit.java b/appe/Digit.java
@@ -0,0 +1,18 @@
+    /**
+     * Tests whether x is a single digit integer.
+     *
+     * @param x the integer to test
+     * @return true if x has one digit, false otherwise
+     */
+    public static boolean isSingleDigit(int x) {
+        if (x > -10 && x < 10) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+
+        System.out.println(isSingleDigit(2));
+        boolean bigFlag = !isSingleDigit2(17);
+
diff --git a/ch08/CodingBat.java b/ch08/CodingBat.java
@@ -0,0 +1,29 @@
+/**
+ * CodingBat examples from Chapter 8.
+ */
+public class CodingBat {
+
+    public static String noX(String str) {
+        if (str.length() == 0) {
+            return "";
+        }
+        char c = str.charAt(0);
+        if (c == 'x') {
+            return noX(str.substring(1));
+        } else {
+            return c + noX(str.substring(1));
+        }
+    }
+
+    public int array11(int[] nums, int index) {
+        if (index >= nums.length) {
+            return 0;
+        }
+        if (nums[index] == 11) {
+            return 1 + array11(nums, index + 1);
+        } else {
+            return array11(nums, index + 1);
+        }
+    }
+
+}
diff --git a/ch08/Exercise.java b/ch08/Exercise.java
@@ -1,4 +1,7 @@
-public class Recursive {
+/**
+ * Stack diagram exercise.
+ */
+public class Exercise {
 
     public static void main(String[] args) {
         System.out.println(prod(1, 4));
diff --git a/ch08/Recurse.java b/ch08/Recurse.java
@@ -1,5 +1,5 @@
 /**
- * Recursion exercise.
+ * Palindrome exercise.
  */
 public class Recurse {
 
diff --git a/ch08/Recursion.java b/ch08/Recursion.java
@@ -4,17 +4,11 @@ public static void main(String[] args) {
         System.out.println("countdown");
         countdown(3);
 
-        System.out.println("countup");
-        countup(3);
-
-        System.out.println("newLine");
-        newLine();
-
         System.out.println("nLines");
         nLines(3);
 
-        System.out.println("threeLine");
-        threeLine();
+        System.out.println("countup");
+        countup(3);
 
         System.out.println("displayBinary");
         displayBinary(23);
@@ -34,12 +28,6 @@ public static void newLine() {
         System.out.println();
     }
 
-    public static void threeLine() {
-        newLine();
-        newLine();
-        newLine();
-    }
-
     public static void nLines(int n) {
         if (n > 0) {
             System.out.println();
diff --git a/ch08/Series.java b/ch08/Series.java
@@ -3,30 +3,7 @@
  */
 public class Series {
 
-    public static void countup(int n) {
-        if (n == 0) {
-            System.out.println("Blastoff!");
-        } else {
-            countup(n - 1);
-            System.out.println(n);
-        }
-    }
-
-    /**
-     * Tests whether x is a single digit integer.
-     *
-     * @param x the integer to test
-     * @return true if x has one digit, false otherwise
-     */
     public static boolean isSingleDigit(int x) {
-        if (x > -10 && x < 10) {
-            return true;
-        } else {
-            return false;
-        }
-    }
-
-    public static boolean isSingleDigit2(int x) {
         return x > -10 && x < 10;
     }
 
@@ -48,12 +25,6 @@ public static int fibonacci(int n) {
 
     public static void main(String[] args) {
 
-        countup(3);
-        System.out.println("Have a nice day.");
-
-        System.out.println(isSingleDigit(2));
-        boolean bigFlag = !isSingleDigit2(17);
-
         int z = 9;
         if (isSingleDigit(z)) {
             System.out.println("z is small");
