算法及其相关

算法基础

队列：先进先出，后进后出

public class dui {    private Object[] objects;    private int size;    private int head;    private int end;    public dui(int size){        this.objects = new Object[size];        this.head = 0;        this.end = 0;        this.size = 0;    }       public void push(Object object) throws Exception{        if(this.size>objects.length)            throw new Exception("Queue is full");        objects[end++] = object;        size++;    }       public Object pop()throws Exception{        if(this.size == 0)         //  return null;           throw new Exception("Queue is empty!");             if(head == objects.length)                this.head = 0;            size--;            return objects[head++];    }       public Object peek() throws Exception{        if(this.size == 0)            throw new Exception("Queue is empty!");        return objects[head];           }}

栈：先进后出，后进先出

public class Stack {    private Object[] objects;    private int head;    private int size;    public Stack (int size){        objects = new Object[size];        this.head = 0;        this.size = 0;    }    public void push(Object object) throws Exception{        if (this.size == objects.length)            throw new Exception("this stack is full");        objects[head++] = object;        size++;    }    public Object pop() throws Exception{        if (size == 0)            throw new Exception("this stack is empty");        size--;        return objects[--head];    }}

斐波那契数列两种实现:递归和非递归

//递归方法public class feibo {    private static int getFibo(int i){        if (i==1) return 1;        if (i==2) return 1;        else             return getFibo(i-1)+getFibo(i-2);    }    public static void main(String[] args){        for(int j=1;j<=20;j++){            System.out.print(getFibo(j)+"\t");            if(j % 5 == 0)                System.out.println();        }    }}

冒泡排序

public class mao {    public static void main(String[] args) {        int[] f={3,5,7,12,9,13,14};        int a;        for(int i=0;i<f.length;i++){            for(int j=0;j<f.length-i-1;j++){                if(f[j]<f[j+1])                {                    a=f[j];                    f[j]=f[j+1];                    f[j+1]=a;                }                       }                   }        System.out.print("最终循环结果" + " ");        for (int i : f) {            System.out.print(i + " ");        }           }}

快速排序

public class Array {    public static int partition(int []array,int lo,int hi){        int key=array[lo];        while(lo<hi){            while(array[lo]<=key&&hi>lo){//从前边找大的                lo++;             }//            array[hi]=array[lo];            while(array[hi]>=key&&hi>lo){//从后边找小的                hi--;            }            array[lo]=array[hi];                    }        array[hi]=key;       return hi;           }    public static void sort(int []array,int lo,int hi){        if(lo>=hi){            return;        }        int index =partition(array,lo,hi);        sort(array,lo,index-1);        sort(array,index+1,hi);         }    public static void main(String[] args) {        int []array={49,27,97,76,13,65,38};        sort(array,0,array.length-1);        for(int i:array){            System.out.print(i+" ");        }    }    }