Completed Lab 009

README.md

@@ -12,11 +12,13 @@
 
 1. Using the [Python Tutor code visualizer](https://pythontutor.com/java.html#mode=edit) for Java, capture an image of a diagram showing the local variables and parameters of main and riddle just before riddle returns for the code below.
     * Save the image taken above to your project as Part1_2.jpg.
+    * ![img.png](Part1_2.jpg)
 2. Answer the following question in the **text** block below:
     * Is the **blank** object mutable or immutable? How can you tell?
-
 ```text
 PUT ANSWER TO #2 HERE
+Yes, the blank object is mutable. You can tell this because the object is adjusted inside the riddle method, which means 
+it can be changed. 
 ```
 
 ```java
@@ -41,13 +43,16 @@ public class Puzzler {
 
 3. Using the [Python Tutor code visualizer](https://pythontutor.com/java.html#mode=edit) for Java, capture a stack diagram showing the state of the below program just before **findCenter** returns.
     * Save the image taken above to your project as Part1_3.jpg.
+    * ![img.png](Part1_3.jpg)
 4. Using the [Python Tutor code visualizer](https://pythontutor.com/java.html#mode=edit) for Java, capture a stack diagram showing the state of the program just before **distance** returns.
     * Save the image taken above to your project as Part1_4.jpg.
+    * ![img.png](Part1_4.jpg)
 5. Answer the following question below in the **text** block below:
     * Explain how the return values from #3 and #4 differ.
 
 ```text
 PUT ANSWER TO #5 HERE
+The return from #3 returns a value, while the return from #4 does not return any value
 ```
 
 ```java
@@ -83,18 +88,21 @@ Recall that aliases are two variables that refer to the same object.
 
 1. Using the [Python Tutor code visualizer](https://pythontutor.com/java.html#mode=edit) for Java, capture a diagram that shows the state of the program just before the end of main.
     * Save the image taken above to your project as Part2_1.jpg.
+    * ![img.png](Part2_1.jpg)
 2. What is the output of the program?
     * Put the output in the text block below
 
 ```text
 PUT ANSWER TO #2 HERE
+(5, 8)
 ```
 
 3. At the end of main, are p1 and p2 aliased? Why or why not?
     * Put your answer in the text block below
 
 ```text
 PUT ANSWER TO #3 HERE
+No, they're not aliased. P1 and P2 both refer to different objects. 
 ```
 
 ```java
@@ -140,8 +148,10 @@ for (int i = 0; i < s.length(); i++) {
 1. Encapsulate the above fragment in a method in the [StringPlayground](src/StringPlayground.java) class that takes a string argument and returns the final value of count.
 2. Test your method with multiple strings, including some that are balanced and some that are not.
     * Screenshot your output and add it to your project as Part3_2.jpg
+    * ![img.png](Part3_2.jpg)
 3. Generalize the code so that it works on any string.
     * What could you do to generalize it more?
+    * You could add square brackets "[]" or curly brackets "{}" to generalize it more.
 
 ## Part 4: Large Numbers
 

src/BigIntRewrite.java

@@ -1,5 +1,18 @@
+import java.math.BigInteger;
 public class BigIntRewrite {
+    public static BigInteger pow(int x, int n) {
+        if (n == 0) return BigInteger.ONE;
+        BigInteger t = pow(x, n / 2);
+        if (n % 2 == 0) {
+            return t.multiply(t);
+        } else {
+            return t.multiply(t).multiply(BigInteger.valueOf(x));
+        }
+    }
     public static void main(String[] args) {
-
+        int x = 4;
+        int n = 10;
+        BigInteger result = pow(x, n);
+        System.out.println(x + " raised to the power of " + n + " is: " + result);
     }
 }

src/StringPlayground.java

@@ -1,4 +1,24 @@
 public class StringPlayground {
+    public static int countParentheses(String s) {
+        int count = 0;
+        for (int i = 0; i < s.length(); i++) {
+            char c = s.charAt(i);
+            if (c == '(') {
+                count++;
+            } else if (c == ')') {
+                count--;
+            }
+        }
+        return count;
+    }
+
     public static void main(String[] args) {
+        String s = "((3 + 7) * 2)";
+        String s2 = "(3 + 7) * 2)";
+        String s3 = "((3 + 7 * 2)";
+
+        System.out.println("Count of parentheses for s: " + countParentheses(s));
+        System.out.println("Count of parentheses for s2: " + countParentheses(s2));
+        System.out.println("Count of parentheses for s3: " + countParentheses(s3));
     }
 }