CSE143 Sample Program handout #2 Client Program ArrayIntListSample.java -------------------------------------- public class ArrayIntListSample { public static void main(String[] args) { ArrayIntList list = new ArrayIntList(25); list.add(3); list.add(7); list.add(11); System.out.println("initial list = " + list); list.add(0, 2); list.add(2, 5); System.out.println("after some adds = " + list); System.out.print("index of:"); for (int i = 1; i < 10; i += 2) System.out.print(" " + i + " -> " + list.indexOf(i)); System.out.println(); System.out.print("get:"); for (int i = 0; i < list.size(); i++) System.out.print(" " + i + " -> " + list.get(i)); System.out.println(); System.out.println("list = " + list); while (list.size() > 0) { int i = (int) (Math.random() * list.size()); list.remove(i); System.out.println("after removing at " + i + " list = " + list); } } } Output of ArrayIntListSample.java --------------------------------- initial list = [3, 7, 11] after some adds = [2, 3, 5, 7, 11] index of: 1 -> -1 3 -> 1 5 -> 2 7 -> 3 9 -> -1 get: 0 -> 2 1 -> 3 2 -> 5 3 -> 7 4 -> 11 list = [2, 3, 5, 7, 11] after removing at 4 list = [2, 3, 5, 7] after removing at 0 list = [3, 5, 7] after removing at 0 list = [5, 7] after removing at 0 list = [7] after removing at 0 list = [] Program ArrayIntList.java ------------------------- // Class ArrayIntList can be used to store a list of integers. public class ArrayIntList { private int[] elementData; // list of integers private int size; // current number of elements in the list public static final int DEFAULT_CAPACITY = 100; // post: constructs an empty list of default capacity public ArrayIntList() { this(DEFAULT_CAPACITY); } // pre : capacity >= 0 // post: constructs an empty list with the given capacity public ArrayIntList(int capacity) { elementData = new int[capacity]; size = 0; } // post: returns the current number of elements in the list public int size() { return size; } // pre : 0 <= index < size() // post: returns the integer at the given index in the list public int get(int index) { return elementData[index]; } // post: creates a comma-separated, bracketed version of the list public String toString() { if (size == 0) { return "[]"; } else { String result = "[" + elementData[0]; for (int i = 1; i < size; i++) { result += ", " + elementData[i]; } result += "]"; return result; } } // post : returns the position of the first occurrence of the given // value (-1 if not found) public int indexOf(int value) { for (int i = 0; i < size; i++) { if (elementData[i] == value) { return i; } } return -1; } // pre : size() < capacity (elementData.length) // post: appends the given value to the end of the list public void add(int value) { elementData[size] = value; size++; } // pre: size() < capacity (elementData.length) && 0 <= index <= size() // post: inserts the given value at the given index, shifting subsequent // values right public void add(int index, int value) { for (int i = size; i > index; i--) { elementData[i] = elementData[i - 1]; } elementData[index] = value; size++; } // pre : 0 <= index < size() // post: removes value at the given index, shifting subsequent values left public void remove(int index) { for (int i = index; i < size - 1; i++) { elementData[i] = elementData[i + 1]; } size--; } }
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Last modified: Wed Mar 31 20:24:43 PDT 2010