└── Drill02.java


/Drill02.java:
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 1 | import java.util.LinkedList;
 2 | import java.util.Queue;
 3 | import java.util.Stack;
 4 | 
 5 | public class Drill02 {
 6 | 	
 7 | 	// -------- Stacks/Queues
 8 | 
 9 | 	// Given a stack as input, return a stack that has the
10 | 	// same values in reverse order.
11 | 	static Stack<Integer> reverseStack(Stack<Integer> in) {
12 | 		Stack<Integer> result = new Stack<Integer>();
13 | 		while (!in.empty()) {
14 | 			result.push(in.pop());
15 | 		}
16 | 		return result;
17 | 	}
18 | 
19 | 	// Given a queue, return a new queue that has the
20 | 	// same values in reverse order
21 | 	static Queue<Integer> reverseQueue(Queue<Integer> in) {
22 | 		Queue<Integer> result = new LinkedList<>();
23 | 		Stack<Integer> temp = new Stack<Integer>();
24 | 		while (!in.isEmpty()) {
25 | 			temp.push(in.remove());	
26 | 		}
27 | 		while (!temp.empty()) {
28 | 			result.add(temp.pop());
29 | 		}
30 | 		return result;
31 | 	}
32 | 	
33 | 	
34 | 	// -------- Recursion
35 | 
36 |     // takes a number of characters to print as a parameter
37 |     // returns a string with one or two asterisks in the middle
38 |     // surrounded by alligators
39 | 	// See the README
40 |     public static String zigzag(int n) {
41 |     	if (n == 1) {
42 |     		return "*";
43 |     	}
44 |     	else if (n == 2) {
45 |     		return "**";
46 |     	}
47 |     	else {
48 |     		return "<" + zigzag(n - 2) + ">";
49 |     	}
50 |     }
51 | 
52 |     // takes a string and a character as parameters and returns 
53 |     // the string with all copies of the character moved to the 
54 |     // end and capitalized
55 |     // See the README
56 |     public static String moveToEnd(String s, char c) {
57 |     	if (s.length() == 0) {
58 |     		return "";
59 |     	}
60 |     	else {
61 |     		String temp = s.substring(1);
62 |     		if (s.toLowerCase().charAt(0) == Character.toLowerCase(c)) {
63 |     			return moveToEnd(temp, c) + Character.toUpperCase(s.charAt(0));
64 |     		}
65 |     		else {
66 |     			return s.charAt(0) + moveToEnd(temp, c);
67 |     		}
68 |     	}
69 |     }
70 | 
71 | }
72 | 


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