loop version and recursive version

InsertSort

 34 void insertSort(int a[], int len){
 35     for (int j = 1; j < len; ++j){
 36         int key = a[j];
 37         int i = j - 1;
 38         while(i >= 0 && a[i] > key){
 39             a[i+1] = a[i];
 40             i--;
 41         }
 42         a[i+1] = key;
 43     }
 44 }
 45
 46 void insertSort_recursive(int a[], int len){
 47     if (len <= 1) return;
 48     insertSort_recursive(a, len-1);
 49     int key = a[len-1];
 50     int i = len - 2;
 51     while(i >= 0 && a[i] > key){
 52         a[i+1] = a[i];
 53         --i;
 54     }
 55     a[i+1] = key;
 56 }