package QueueAndStack;public class MyStack {private long[] arr;private int top;public MyStack() {arr = new long[10];top = -1;}public MyStack(int maxSize) {arr = new long[maxSize];top = -1;}public void push(long val) {arr[++top] = val;}public long pop() {return arr[top–];}public long peek() {return arr[top];}public boolean isEmpty() {return top == -1;}public boolean isFull() {return top == arr.length – 1;}public static void main(String[] args) {MyStack st = new MyStack(4);st.push(23);st.push(12);st.push(1);st.push(90);while (!st.isEmpty()) {System.out.println(st.pop());}}}
上面是stack的实现,十分简单.直接上代码.
下面是一个简单的队列,同样是简单粗糙的实现:
package QueueAndStack;public class MyQueue {long[] arr;// 有效数据的大小int elements;// 队头int front;// 队尾int end;public MyQueue() {arr = new long[10];elements = 0;front = 0;end = -1;}public MyQueue(int maxSize) {arr = new long[maxSize];elements = 0;front = 0;end = -1;}public void insert(long val) {arr[++end] = val;elements++;}public long remove() {elements–;return arr[front++];}public long peek() {return arr[front];}public boolean isEmpty() {return elements == 0;}public boolean isFull() {return elements == arr.length;}public static void main(String[] args) {MyQueue qu = new MyQueue(3);qu.insert(1);qu.insert(2);qu.insert(3);qu.insert(4);qu.insert(5);qu.insert(6);while (!qu.isEmpty()) {System.out.println(qu.remove());}}}
执行上面的结果,很容易发现这个错 . 上面的这个队列,虽然可以简单的实现,先进先出的原则,但是,无法处理队列溢出问题
下面附一个队列溢出问题的解决方案:
package QueueAndStack;public class MyCycleQueue extends MyQueue { private int count = 0; public MyCycleQueue() { } public MyCycleQueue(int maxSize) { super(maxSize); } @Override public void insert(long val) { if (count < arr.length) { end++; arr[end] = val; elements++; } else { end = (count % arr.length); front = end + 1; if (front == arr.length) { front = 0; } arr[end] = val; } count++; } @Override public long remove() { elements–; if (count > arr.length) { front = count % arr.length; long val = arr[front]; } count–; return arr[front++]; } public static void main(String[] args) { MyQueue qu = new MyCycleQueue(3); qu.insert(1); qu.insert(2); qu.insert(3); qu.insert(4); qu.insert(5); qu.insert(6); qu.insert(7); qu.insert(8); while (!qu.isEmpty()) { System.out.println(qu.remove()); System.out.println(">>>> "+qu.elements); } }}这是一个循环队列, 如果队列溢出了,则会自动抛弃旧的数据;
，得意时应善待他人，因为你失意时会需要他们
