[Function add]

1.Realized a stack by lusing array.

Author: Seanforfun

Algorithm(4th_Edition)/algorithm_note.txt

@@ -113,13 +113,38 @@
 
 11. 栈 LIFO队列：
 	接口：ca.mcmaster.chapter.one.stuck.Stack<T>
-	public interface Stack<T> extends Iterable<T> {
+	public interface MyStack<T>{
 		void push(T t);
 		T pop();
 		Boolean isEmpty();
 		Integer size();
 	}
 
+	->定容字符串栈：
+	public class FixedCapacityStackOfString<T> implements MyStack<T> {
+		private T[] a;
+		private int size;
+		public FixedCapacityStackOfString(int capacity){ a = (T[])new Object[capacity]; }	//无法泛型数组，所以创建一个Object类，再转型为泛型类。
+		public void push(T t) {
+			if(size == a.length)
+				this.resize(a.length * 2);
+			a[size++]  = t;
+		}
+		public T pop() {
+			if(size > 0 && size < a.length/4 )	this.resize(a.length / 2);
+			return (T)a[--size];
+		}
+		public Boolean isEmpty() { return size == 0;}
+		public Integer size() {	return size;}
+		public void resize(int capacity){
+			if(capacity < size) return;
+			T[] temp = (T[])new Object[capacity];
+			for(int i = 0; i < size; i++)
+				temp[i] = a[i];
+			a = temp;
+		}		
+	}
+	
 12. 装箱拆箱：
 	1.基本数据类型和封装数据类型之间的转换。
 	自动装箱(AutoBoxing):从基本数据类型转化成封装数据类型。int->Integer

Algorithm(4th_Edition)/lib/algs4.jar

@@ -1,30 +1,40 @@
 package ca.mcmaster.chapter.one.stack;
 
-import java.util.Iterator;
-
-public class FixedCapacityStackOfString implements Stack<String> {
-	private String[] a;
-	public FixedCapacityStackOfString(int capacity){
-		a = new String[ca]
-	}
-	
-	public Iterator<String> iterator() {
-		return null;
-	}
-	
-	public void push(String t) {
-
+public class FixedCapacityStackOfString<T> implements MyStack<T> {
+	private T[] a;
+	private int size;
+	@SuppressWarnings("unchecked")
+	public FixedCapacityStackOfString(int capacity){ a = (T[])new Object[capacity]; }
+	public void push(T t) {
+		if(size == a.length)
+			this.resize(a.length * 2);
+		a[size++]  = t;
 	}
-
-	public String pop() {
-		return null;
+	public T pop() {
+		if(size > 0 && size < a.length/4 )	this.resize(a.length / 2);
+		return (T)a[--size];
 	}
-
-	public Boolean isEmpty() {
-		return null;
+	public Boolean isEmpty() { return size == 0;}
+	public Integer size() {	return size;}
+	@SuppressWarnings("unchecked")
+	public void resize(int capacity){
+		if(capacity < size) return;
+		T[] temp = (T[])new Object[capacity];
+		for(int i = 0; i < size; i++)
+			temp[i] = a[i];
+		a = temp;
 	}
-
-	public Integer size() {
-		return null;
+	
+	public static void main(String[] args){
+		FixedCapacityStackOfString<String> stack = new FixedCapacityStackOfString<String>(100);
+		stack.resize(120);
+		for(int i = 0; i < 10; i ++)
+			stack.push("" + i);
+		System.out.println(stack.isEmpty());
+		int size = stack.size();
+		for(int i = 0; i < size; i++){
+			System.out.println(stack.pop());
+		}
+		System.out.println(stack.isEmpty());
 	}
 }

Algorithm(4th_Edition)/src/ca/mcmaster/chapter/one/stack/FixedCapacityStackOfString.java

@@ -1,6 +1,6 @@
 package ca.mcmaster.chapter.one.stack;
 
-public interface Stack<T> extends Iterable<T> {
+public interface MyStack<T>{
 	void push(T t);
 	T pop();
 	Boolean isEmpty();