JAVA自己实现List接口Stack

简介package集合.Stack;importjava.util.Arrays;importjava.util.EmptyStackException;importjava.util.Vector;publicclassMyStack{//底层数组默认长度为0privateObject[]myStack=newObject[10];//sizeprivateintsize=0;publicMySta

JAVA自己实现List接口Stack


package 集合.Stack;

import java.util.Arrays;
import java.util.EmptyStackException;
import java.util.Vector;

public class MyStack {
    //底层数组默认长度为10
    private Object[] myStack = new Object[10];
    //size
    private int size = 0;

    public MyStack() {

    }

    //push
    public Object push(Object obj) {
        //先判断是否需要扩容
        if(size>=myStack.length){
            myStack = Arrays.copyOf(myStack,myStack.length*2);
        }
        //添加元素
        myStack[size++] = obj;
        //size++;
        return obj;
    }

    //pop弹出栈顶元素
    public Object pop() {
        Object obj = peek();
        //忽略栈顶元素
        size--;
        return obj;
    }

    //peek查找栈顶元素
    public Object peek() {
        if(empty()){
           throw new EmptyStackException();
        }
        return myStack[size - 1];
    }

    //empty判断栈是否为空
    public boolean empty() {
        return size == 0;
    }

    //search查找栈中第一出线的元素
    public int  search(Object obj) {
        for(int i = size -1,j=1;i>=0;i--,j++){
            if(myStack[i] == obj||myStack[i]!=null&&myStack[i].equals(obj)){
                return  j;
            }
        }
        return -1;
    }

    @Override
    public String toString() {
        Object[] strstack = new Object[size];
        System.arraycopy(myStack,0,strstack,0,size);
        for(int i=size-1;i>=size/2;i--){
            Object temp = strstack[i];
            strstack[i] = strstack[size-i-1];
            strstack[size-i-1] = temp;
        }

        return Arrays.toString(strstack);
    }
}
本文转自:https://blog.51cto.com/12013190/2430837
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