常用排序算法实现（java）

package Sort; /** * 归并排序 */ public class MergeSort { private static Comparable[] temp; //辅助数组 public static void sort(Comparable[] a){ temp = new Comparable[a.length]; sort(a,0,a.length-1); } //将数组a[lo..hi]进行排序 private static void sort(Comparable[] a,int lo ,int hi){ if(lo>=hi) return; int mid = lo+(hi-lo)/2; sort(a,lo,mid);//递归的对左边进行排序 sort(a,mid+1,hi); //递归的对右边进行排序 merge(a,lo,mid,hi); //合并左右两边 } //将两个有序的数组a[lo..mid]和a[mid+1..hi]合并为一个有序的数组，用到一个辅助数组temp public static void merge(Comparable[] a,int lo,int mid,int hi){ int i=lo,j=mid+1; for(int k=lo;k<=hi;k++) //将数组a复制到辅助数组temp中 temp[k] = a[k]; for(int k=lo;k<=hi;k++) if(i>mid) a[k]=temp[j++]; //左半边取尽，直接复制右半边剩余的元素到数组中 else if(j>hi) a[k] = temp[i++]; //右半边取尽，直接复制左半边剩余的元素到数组中 else if(less(temp[j],temp[i])) a[k]=temp[j++]; //右半边的当前元素比左半边的当前元素小，取右半边 else a[k]=temp[i++]; //左半边的当前元素比右半边的当前元素小，取左半边 } private static boolean less(Comparable v ,Comparable w){ return v.compareTo(w)<0; } private static void show(Comparable[] a){ for(int i=0;i<a.length;i++) System.out.print(a[i]+" "); System.out.println(); } private static void exch(Comparable[] a ,int i,int j){ Comparable t = a[i];a[i] = a[j]; a[j] = t; } public static boolean isSorted(Comparable[] a){ for(int i = 1; i<a.length;i++) if(less(a[i],a[i-1])) return false; return true; } public static void main(String[] args) { String[] buff = {"bed","bug","bed","dad","yes","i","am","ok"}; sort(buff); show(buff); } }