重温经典之排序 java实现

重新写一遍，都忘记了！

No.1  快排

public class FastSort {
    public static void main(String[] args)throws Exception{
        int[] a = {10, 1, 2, 3, 7, 3, 8, 5, 6, 4};
        FastSort b1 = new FastSort();
        b1.sort(a,0,a.length-1);
    }
    void sort(int[] a ,int l ,int r)throws Exception{
        int i,j,t,temp;
        i = l ;
        j = r ;
        temp = a[l];
        if(l>r){
            return;
        }
        while (i!=j){
            while(i<j && a[j]>=temp){
                j--;
            }
            while(i<j && a[i]<=temp){
                i++;
            }
            if(i<j){
                t = a[i];
                a[i] = a[j];
                a[j] = t ;
            }
        }
        a[l] = a[i];
        a[i] = temp;
        System.out.print("/");
        for(int h=0;h<a.length;h++){
            System.out.print(a[h]+" ");
        }
        sort(a , l , i-1);
        sort(a , i+1 , r);
    }
}

No.2 冒泡排序

public class Bubblesort {
    public static void main(String []args){
        int []a = {3,5,72,3,8,90};
        sort(a);
    }
    public static void sort(int []a){
        int temp ;
        for(int i = a.length -1 ; i > 0 ; i--){
            for(int j = 0 ; j < i ; j++){
                if(a[j+1] < a[j]){
                    temp = a[j+1];
                    a[j+1] = a[j];
                    a[j] = temp;
                }
            }
        }
        for(int k = 0 ;k<a.length;k++){
            System.out.print(a[k]+",");
        }
    }
}

No.3 插入排序

public class Insertsort {
    public static void main(String[] args){
        int []a = {3,4,4,2,5,4,6,3,2};
        sort(a);
    }
    static void sort(int[] a){
        for(int i = 1 ; i < a.length ; i++){
            for(int j = i ; j > 0 ; j--){
                if(a[j]<a[j-1]){
                    int temp = a[j];
                    a[j] = a[j-1];
                    a[j-1] = temp;
                }
            }
        }
        for(int k = 0;k<a.length;k++)
            System.out.print(a[k]+" ");
    }
}