From c82e3b3b2de0633317ec8fc85925e91422820597 Mon Sep 17 00:00:00 2001 From: "Benjamin J. Culkin" Date: Sun, 8 Oct 2017 22:39:59 -0300 Subject: Start splitting into maven modules --- .../main/java/bjc/utils/esodata/QueueStack.java | 88 ++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 base/src/main/java/bjc/utils/esodata/QueueStack.java (limited to 'base/src/main/java/bjc/utils/esodata/QueueStack.java') diff --git a/base/src/main/java/bjc/utils/esodata/QueueStack.java b/base/src/main/java/bjc/utils/esodata/QueueStack.java new file mode 100644 index 0000000..850598a --- /dev/null +++ b/base/src/main/java/bjc/utils/esodata/QueueStack.java @@ -0,0 +1,88 @@ +package bjc.utils.esodata; + +import java.util.Deque; +import java.util.LinkedList; + +/** + * A FIFO implementation of a stack. + * + * @param + * The datatype stored in the stack. + * @author Ben Culkin + */ +public class QueueStack extends Stack { + private final Deque backing; + + /** + * Create a new empty stack queue. + * + */ + public QueueStack() { + backing = new LinkedList<>(); + } + + @Override + public void push(final T elm) { + backing.add(elm); + } + + @Override + public T pop() { + if (backing.isEmpty()) throw new StackUnderflowException(); + + return backing.remove(); + } + + @Override + public T top() { + if (backing.isEmpty()) throw new StackUnderflowException(); + + return backing.peek(); + } + + @Override + public int size() { + return backing.size(); + } + + @Override + public boolean empty() { + return backing.size() == 0; + } + + @SuppressWarnings("unchecked") + @Override + public T[] toArray() { + return (T[]) backing.toArray(); + } + + @Override + public String toString() { + return String.format("QueueStack [backing=%s]", backing); + } + + @Override + public int hashCode() { + final int prime = 31; + int result = 1; + + result = prime * result + (backing == null ? 0 : backing.hashCode()); + + return result; + } + + @Override + public boolean equals(final Object obj) { + if (this == obj) return true; + if (obj == null) return false; + if (!(obj instanceof QueueStack)) return false; + + final QueueStack other = (QueueStack) obj; + + if (backing == null) { + if (other.backing != null) return false; + } else if (!backing.equals(other.backing)) return false; + + return true; + } +} -- cgit v1.2.3