» CS 245 Lecture 8

CS 245 Lecture 8 – Arrays

February 13, 2014 by Chris Johnson. Filed under cs245, lectures, spring 2014.

Agenda

what ?s
think about this
OurrayList
program this
a spellchecker

TODO

Read pages 61-79 in Data Structures. 1/4 sheet.

Think About This

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Program This

constructor
void add(String o)
int size()
void remove(int i)
void remove(String s)
int indexOf(String s)
String get(int i)

Code

Table.java

package lecture08;

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Insets;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JTable;
import javax.swing.border.Border;
import javax.swing.table.DefaultTableModel;

public class Table extends JFrame {
  public Table() {
    JTable grid = new JTable(8, 4);
    DefaultTableModel model = (DefaultTableModel) grid.getModel();
    model.setValueAt("a", 0, 1);
    
    grid.setGridColor(Color.MAGENTA);
    grid.setShowGrid(true);
    add(grid);
    
    pack();
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setVisible(true);
  }
  
  public static void main(String[] args) {
    new Table();
  }
}

BigArray.java

package lecture08;

public class BigArray {
  public static void main(String[] args) {
    int i = 1;
    while (true) {
      try {
        int[] nums = new int[Integer.MAX_VALUE - i];
        System.out.println(i);
        System.out.println(Integer.MAX_VALUE - i);
        break;
      } catch (OutOfMemoryError e) {
        i += 1000;
      }
    }
    // nums[i]
  }
}

OurrayList.java

package lecture08;

public class OurrayList {
  private String[] items;
  private int itemCount;
  
  public OurrayList(int initialCapacity) {
    items = new String[initialCapacity];
    itemCount = 0;
  }
  
  public OurrayList() {
    this(10);
  }
  
  public int size() {
    return itemCount;
  }
  
  public String get(int i) {
    if (i < 0 || i >= itemCount) {
      throw new IndexOutOfBoundsException("Hey, foobag! " + i + " isn't welcome here.");
    }
    return items[i];
  }
  
  public void add(String s) {
    // Are we full?
    if (itemCount == items.length) {
      String[] moreItems = new String[2 * items.length];
      for (int i = 0; i < items.length; ++i) {
        moreItems[i] = items[i];
      }
      items = moreItems;
    }
    
    items[itemCount] = s;
    ++itemCount;
  }
  
  public void remove(int i) {
    for (int j = i; j < itemCount; ++j) {
      items[j] = items[j + 1];
    }
    items[itemCount] = null;
  }
}

Haiku

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