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Added four required methods plus toString() for debuggin/output to bo… #16

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2 changes: 1 addition & 1 deletion .idea/misc.xml
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6 changes: 6 additions & 0 deletions .idea/vcs.xml
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194 changes: 193 additions & 1 deletion src/Main.java
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Original file line number Diff line number Diff line change
@@ -1,12 +1,204 @@
public class Main {
public static void main(String[] args) {
System.out.println("Hello world!");
//System.out.println("Hello world!");

System.out.println();
System.out.println("-------------------------- Testing ResizingArrayDeque --------------------------");
System.out.println();
Deque<String> d1 = new ResizingArrayDeque<>();
// some test code here

// Testing addFirst() on empty/non-empty list - I implemented toString() to ease this ...
d1.addFirst("a");
d1.addFirst("b");
d1.addFirst("c");
d1.addFirst("d");
d1.addFirst("e");
d1.addFirst("f");
d1.addFirst("g");
d1.addFirst("h");
d1.addFirst("i");
d1.addFirst("j");
d1.addFirst("k");
d1.addFirst("l");

// should print in reverse order of addition ...
System.out.println("Testing addFirst on empty/non-empty, a..l, should print in reverse order");
System.out.println(d1);

/// test addLast on non-empty list
d1.addLast("m");
d1.addLast("n");
d1.addLast("o");
d1.addLast("p");
d1.addLast("q");
d1.addLast("r");
d1.addLast("s");
d1.addLast("t");
d1.addLast("u");
d1.addLast("v");

// should append these letters to prior in added order
System.out.println();
System.out.println("Testing addLast() on non-empty list, m..v, should display in order added");
System.out.println(d1);

d1 = new ResizingArrayDeque<>();

// testing addLast on empty list
d1.addLast("m");
d1.addLast("n");
d1.addLast("o");
d1.addLast("p");
d1.addLast("q");
d1.addLast("r");
d1.addLast("s");
d1.addLast("t");
d1.addLast("u");
d1.addLast("v");

System.out.println();
System.out.println("Testing addLast() on empty list, should display m..v in order");
System.out.println(d1);

System.out.println("Removing / printing 1st item in list");
System.out.println(d1.removeFirst());
System.out.println("Removing / printing 1st item in list");
System.out.println(d1.removeFirst());
System.out.println("Resulting list");
System.out.println(d1);

d1 = new ResizingArrayDeque<>();
System.out.println("Removing / printing item from empty list");
System.out.println(d1.removeFirst());
d1.addLast("a");
System.out.println("Removing / printing item from list that contains just 'a'");
System.out.println(d1.removeFirst());
System.out.println("Resulting list (should be empty/blank)");
System.out.println(d1);
System.out.println("d1.size: " + d1.size());

d1.addLast("a");
d1.addLast("b");
d1.addLast("c");
d1.addLast("d");
d1.addLast("e");

System.out.println();
System.out.println("Recreated list, added letters a..e");
System.out.println(d1);
System.out.println();

System.out.println("Testing removeLast(), should remove in reverse order, i.e. (e, d, c, b, a)");
System.out.println(d1.removeLast());
System.out.println(d1.removeLast());
System.out.println(d1.removeLast());
System.out.println(d1.removeLast());
System.out.println(d1.removeLast());
System.out.println("Resulting list - should be empty/blank");
System.out.println(d1);
System.out.println("d1.size: " + d1.size());
System.out.println();

System.out.println();
System.out.println();
System.out.println("-------------------------- Testing SinglyLinkedDeque --------------------------");
System.out.println();
Deque<String> d2 = new SinglyLinkedDeque<>();
// some test code here

// Testing addFirst() on empty/non-empty list - I implemented toString() to ease this ...
d2.addFirst("a");
d2.addFirst("b");
d2.addFirst("c");
d2.addFirst("d");
d2.addFirst("e");
d2.addFirst("f");
d2.addFirst("g");
d2.addFirst("h");
d2.addFirst("i");
d2.addFirst("j");
d2.addFirst("k");
d2.addFirst("l");

// should print in reverse order of addition ...
System.out.println("Testing addFirst on empty/non-empty, a..l, should print in reverse order");
System.out.println(d2);

/// test addLast on non-empty list
d2.addLast("m");
d2.addLast("n");
d2.addLast("o");
d2.addLast("p");
d2.addLast("q");
d2.addLast("r");
d2.addLast("s");
d2.addLast("t");
d2.addLast("u");
d2.addLast("v");

// should append these letters to prior in added order
System.out.println();
System.out.println("Testing addLast() on non-empty list, m..v, should display in order added");
System.out.println(d2);

// start with an empty list
d2 = new SinglyLinkedDeque<>();

// testing addLast on empty list
d2.addLast("m");
d2.addLast("n");
d2.addLast("o");
d2.addLast("p");
d2.addLast("q");
d2.addLast("r");
d2.addLast("s");
d2.addLast("t");
d2.addLast("u");
d2.addLast("v");

System.out.println();
System.out.println("Testing addLast() on empty list, should display m..v in order");
System.out.println(d2);

System.out.println("Removing / printing 1st item in list");
System.out.println(d2.removeFirst());
System.out.println("Removing / printing 1st item in list");
System.out.println(d2.removeFirst());
System.out.println("Resulting list");
System.out.println(d2);

d2 = new SinglyLinkedDeque<>();
System.out.println("Removing / printing item from empty list");
System.out.println(d2.removeFirst());
d2.addLast("a");
System.out.println("Removing / printing item from list that contains just 'a'");
System.out.println(d2.removeFirst());
System.out.println("Resulting list (should be empty/blank)");
System.out.println(d2);
System.out.println("d2.size: " + d2.size());

d2.addLast("a");
d2.addLast("b");
d2.addLast("c");
d2.addLast("d");
d2.addLast("e");

System.out.println();
System.out.println("Recreated list, added letters a..e");
System.out.println(d2);
System.out.println();

System.out.println("Testing removeLast(), should remove in reverse order, i.e. (e, d, c, b, a)");
System.out.println(d2.removeLast());
System.out.println(d2.removeLast());
System.out.println(d2.removeLast());
System.out.println(d2.removeLast());
System.out.println(d2.removeLast());
System.out.println("Resulting list - should be empty/blank");
System.out.println(d2);
System.out.println("d2.size: " + d2.size());
System.out.println();

}
}
78 changes: 54 additions & 24 deletions src/ResizingArrayDeque.java
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Original file line number Diff line number Diff line change
@@ -1,3 +1,11 @@
import java.util.Arrays;

/**
* This class was created by Ken Hang, four methods addFirst, addLast, removeFirst,
* and removeLast were implemented by Paul with interfaces by Ken.
*
* @author Paul Woods, Ken Hang
*/
public class ResizingArrayDeque<ItemType> implements Deque<ItemType> {
// constants
public static int DEFAULT_CAPACITY = 10;
Expand Down Expand Up @@ -31,11 +39,20 @@ public int size() {
*/
@Override
public void addFirst(ItemType item) {
// consider the case of adding to an empty list
// consider the case of adding to a non-empty list
// Properties/Methods: DEFAULT_CAPACITY = 10, ItemType[] data, int size, checkSize()

// There is a private helper method checkSize() defined below to check/resize
// that you can call as needed to check if the array is full and resize it.
// Check size of underlying array, increase if necessary
checkSize();

// reposition all elements one place up
for (int i = size; i > 0; i--) {
data[i] = data[i-1];
}

// assign new data to data[0], as that has been moved to data[1]
data[0] = item;

++size;
}

/**
Expand All @@ -45,11 +62,9 @@ public void addFirst(ItemType item) {
*/
@Override
public void addLast(ItemType item) {
// consider the case of adding to an empty list
// consider the case of adding to a non-empty list
checkSize();

// There is a private helper method checkSize() defined below to check/resize
// that you can call as needed to check if the array is full and resize it.
data[size++] = item;
}

/**
Expand All @@ -59,18 +74,22 @@ public void addLast(ItemType item) {
*/
@Override
public ItemType removeFirst() {
// check if empty

// if empty: do nothing and return null
if (size == 0) {
return null;
}

// if there's only one item: is this a special case?
// non-empty, save 1st element, and shift all others down 1 place
ItemType item = data[0];
for (int i = 0; i < size - 1; i++) {
data[i] = data[i + 1];
}

// if not empty:
// 0. figure out a way to access the item in the front
// 1. make a variable to save a copy of the item at the front
// 2. remove the item at the front
// 3. return the variable that has the saved copy of the item at the front
--size;

return null;
// return 1st element that was saved
return item;
}

/**
Expand All @@ -80,18 +99,18 @@ public ItemType removeFirst() {
*/
@Override
public ItemType removeLast() {
// check if empty

// if empty: do nothing and return null
if (size == 0) {
return null;
}

// if there is only one item: is this a special case?
ItemType item = data[size-1];
data[size-1] = null;

// if not empty, has more than one item:
// 0. figure out a way to access the item in the back
// 1. make a variable to save a copy of the item at the back
// 2. remove the item at the back
// 3. return the variable that has the saved copy of the item at the back
--size;

return null;
return item;
}

// helper method to check to see if the size has reached the capacity
Expand All @@ -116,4 +135,15 @@ private void checkSize() {
temp = null;
} // end of if (need to resize)
}

@Override
public String toString() {
String s = "";
for (int i = 0; i < size; i++) {
s += data[i];
if (i < size-1)
s += ", ";
}
return s;
}
}
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