1 void mergeAdd(int arr[], int left, int mid, int right, int *temp){
2 int i = left;
3 int j = mid + 1;
4 int k = left;//临时下标
5 while (i <= mid&&j <= right){
6 if (arr[i] < arr[j]){
7 temp[k++] = arr[i++];
8 }
9 else{
10 temp[k++] = arr[j++];
11 }
12 }
13 while (i <= mid){
14 temp[k++] = arr[i++];
15 }
16 while (j <= right){
17 temp[k++] = arr[j++];
18 }
22 memcpy(arr + left, temp + left, sizeof(int)*(right - left+1));
23 }
24 void mergeSort(int arr[],int left,int right,int *temp){
25 int mid = 0;
26 if (left < right){ //归并排序采用先分再并的思想，效率上为O(nlgn), 空间上为O(n),需要耗用多一倍的空间
27 mid = left + (right - left) / 2;
28 mergeSort(arr, left, mid, temp);
29 mergeSort(arr, mid + 1, right, temp);
30 mergeAdd(arr, left, mid, right, temp);
31 }
32 }