几种算法，采用java实现

//冒泡排序,两两排，不断将大或小值向后移。public int[] bubbleSort(int[] old){    for(int i=0;i<old.length;i++)    {        for(int j=0;j<old.length-i-1;j++)        {            if(old[j]>old[j+1])            {                int temp=old[j];                old[j]=old[j+1];                old[j+1]=temp;            }        }    }

return old;}

//插入排序,不断将i前数列排出顺序，再将第i列插进去public int[] insertSort(int[] old){    for(int i=1;i<old.length;i++)    {        int current=old[i];        int j=i-1;        while(j>=0&&old[j]>current)        {            old[j+1]=old[j];            j--;        }        old[j+1]=current;    }    return old;}

//希尔排序,插入排序升级版，1.划块2.跳区3.反减public int[] shellSort(int[] a){    for(int incurrent=a.length/2;incurrent>0;incurrent/=2)        for(int i=0;i<a.length;i+=incurrent)            for(int j=i;j>0;j-=incurrent)                if(a[j]<a[j-incurrent])                {                    int temp=a[j];                    a[j]=a[j-incurrent];                    a[j-incurrent]=temp;                }    return a;}

//选择排序 即一次选出最大/最小放在最前面public int[] chooseSort(int[] old){    for(int i=0;i<old.length;i++)        for(int j=i+1;j<old.length;j++)            if(old[j]<old[i])            {                int temp = old[j];                old[j] = old[i];                old[i] = temp;            }    return old;}