有两个排序数组A1和A2，内存在A1的末尾有足够多的空余空间容纳A2，实现一个函数，把A2 插入到A1，并且是有序的

 1 class solution{
 2     public static void merge(int[] A1, int[] A2, int lengthA1, int lengthA2){
 3         int indexA1 = lengthA1-1;
 4         int indexA2 = lengthA2-1;
 5         int indexMerged = lengthA1+indexA2-1;
 6         
 7         while(indexA1>=0&&indexA2>=0){
 8             if(A1[indexA1] >= A2[indexA2]){
 9                 A1[indexMerged] = A1[indexA1];
10                 indexMerged--;
11                 indexA1--;
12             }else{
13                 A1[indexMerged] = A2[indexA2];
14                 indexMerged--;
15                 indexA2--;
16             }
17         }
18         
19         while(indexA1>=0){
20             A1[indexMerged] = A1[indexA1];
21             indexMerged--;
22             indexA1--;
23         }
24         
25         while(indexA2>=0){
26             A1[indexMerged] = A2[indexA2];
27             indexMerged--;
28             indexA2--;
29         }
30         
31     }
32 
33 }