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refactor: QueueUsingTwoStacks (#5427)

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refactor: QueueUsingTwoStacks

Co-authored-by: alxkm <alx@alx.com>
This commit is contained in:
Alex Klymenko
2024-08-28 22:25:46 +02:00
committed by GitHub
parent 203d544668
commit 6b7a1fdbe8
2 changed files with 151 additions and 76 deletions
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82
src/main/java/com/thealgorithms/others/QueueUsingTwoStacks.java
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@ -15,17 +15,14 @@ import java.util.Stack;
*
* @author sahilb2 (https://www.github.com/sahilb2)
*/
class QueueWithStack {
// Stack to keep track of elements inserted into the queue
private Stack<Object> inStack;
// Stack to keep track of elements to be removed next in queue
private Stack<Object> outStack;
public class QueueUsingTwoStacks {
private final Stack<Object> inStack;
private final Stack<Object> outStack;
/**
* Constructor
*/
QueueWithStack() {
public QueueUsingTwoStacks() {
this.inStack = new Stack<>();
this.outStack = new Stack<>();
}
@ -94,7 +91,7 @@ class QueueWithStack {
* @return true if the inStack is empty.
*/
public boolean isInStackEmpty() {
return (inStack.size() == 0);
return (inStack.isEmpty());
}
/**
@ -103,73 +100,6 @@ class QueueWithStack {
* @return true if the outStack is empty.
*/
public boolean isOutStackEmpty() {
return (outStack.size() == 0);
}
}
/**
* This class is the example for the Queue class
*
* @author sahilb2 (https://www.github.com/sahilb2)
*/
public final class QueueUsingTwoStacks {
private QueueUsingTwoStacks() {
}
/**
* Main method
*
* @param args Command line arguments
*/
public static void main(String[] args) {
QueueWithStack myQueue = new QueueWithStack();
myQueue.insert(1);
System.out.println(myQueue.peekBack()); // Will print 1
// instack: [(top) 1]
// outStack: []
myQueue.insert(2);
System.out.println(myQueue.peekBack()); // Will print 2
// instack: [(top) 2, 1]
// outStack: []
myQueue.insert(3);
System.out.println(myQueue.peekBack()); // Will print 3
// instack: [(top) 3, 2, 1]
// outStack: []
myQueue.insert(4);
System.out.println(myQueue.peekBack()); // Will print 4
// instack: [(top) 4, 3, 2, 1]
// outStack: []
System.out.println(myQueue.isEmpty()); // Will print false
System.out.println(myQueue.remove()); // Will print 1
System.out.println((myQueue.isInStackEmpty()) ? "null" : myQueue.peekBack()); // Will print NULL
// instack: []
// outStack: [(top) 2, 3, 4]
myQueue.insert(5);
System.out.println(myQueue.peekFront()); // Will print 2
// instack: [(top) 5]
// outStack: [(top) 2, 3, 4]
myQueue.remove();
System.out.println(myQueue.peekFront()); // Will print 3
// instack: [(top) 5]
// outStack: [(top) 3, 4]
myQueue.remove();
System.out.println(myQueue.peekFront()); // Will print 4
// instack: [(top) 5]
// outStack: [(top) 4]
myQueue.remove();
// instack: [(top) 5]
// outStack: []
System.out.println(myQueue.peekFront()); // Will print 5
// instack: []
// outStack: [(top) 5]
myQueue.remove();
// instack: []
// outStack: []
System.out.println(myQueue.isEmpty()); // Will print true
return (outStack.isEmpty());
}
}