关于归并算法跟循环算法

1.归并算法对两个有序数组的排序速度远大于for循环算法
2.归并算法无法对两个无序数组排序

package study03;

import java.util.Arrays;

public class Concat {

    //归并算法
    public int[] concat(int[] arr1, int[] arr2){
        int index1 = 0;
        int index2 = 0;
        int indexTemp = 0;
        int[] temp = new int[arr1.length+arr2.length];
        while (index1!=arr1.length&&index2 != arr2.length){
            if (arr1[index1]<arr2[index2]){
                temp[indexTemp] = arr1[index1];
                index1++;
            }else {
                temp[indexTemp] = arr2[index2];
                index2++;
            }
            indexTemp++;
        }

        if (index1!=arr1.length){
            for (int i = index1; i < arr1.length; i++,index1++,indexTemp++) {
                temp[indexTemp] = arr1[index1];
            }
        }else if (index2 != arr1.length){
            for (int i = index2; i < arr2.length; i++,index2++,indexTemp++) {
                temp[indexTemp] = arr2[index2];
            }
        }
        return temp;
    }

    //循环算法
    public int[] concat2(int[] arr1, int[] arr2){
        int[] temp = new int[arr1.length + arr2.length];

        for (int i = 0; i < arr1.length; i++) {
            temp[i] = arr1[i];
        }

        for (int i = 0; i < arr2.length; i++) {
            temp[arr1.length+i] = arr2[i];
        }
        for (int i = 0; i < temp.length-1; i++) {
            for (int j = 0; j < temp.length - i - 1; j++) {
                if (temp[j]>temp[j+1]){
                    int t = temp[j];
                    temp[j] = temp[j+1];
                    temp[j+1] = t;
                }
            }
        }
        return temp;
    }
}