合并排序

import java.util.Arrays;

/**
 * 合并排序
 *
 */
public class MergeSort {
    public static void main(String[] args) {
        int s[]={89998,9,3,2,98,236,115,5,9,9087,100,67,1,756};
        int r[]=map(s);

        //打印结果
        StringBuilder sb=new StringBuilder();
        for (int i = 0; i < r.length; i++) {
            sb.append(r[i]);
            sb.append(",");
        }
        System.out.println(sb.toString());
    }

    public static int[] map(int one[]){
        if(one.length>2){
            int [] head= Arrays.copyOf(one,one.length/2);
            int[]  r1=map(head);
            int [] tail=Arrays.copyOfRange(one,one.length/2,one.length);
            int [] r2=map(tail);
            return merge(r1,r2);
        }else if(one.length==2){
            if(one[0]>one[1]){
                int temp=one[0];
                one[0]=one[1];
                one[1]=temp;
            }
           return one;
        }else{
            return one;
        }
    }
    public static int[] merge(int[] r1,int [] r2){
        int [] merge=new int[r1.length+r2.length];
        int i1=0,i2=0;
        for(int i=0;i<(r1.length+r2.length);i++){
            if((r1.length!=i1)&&(i2==r2.length||r1[i1]<r2[i2])){
                merge[i]=r1[i1];
                i1++;
            }else{
                merge[i]=r2[i2];
                i2++;
            }
        }
        return merge;
    }

}