53rd and 54th writing of insertion sort (CLRS pseudocode, C pseudocode) : insertion sort with sentinel

To deepen my understanding of insertion sort. I start to think through different variants of insertion sort.  The most trivial one is to use sentinel in the sort. 

In CLRS version, it looks like

1,  A[0] = -infinity

2,  for j = 1  to N

3,      key = A[j]

4,      i = j -1

5,      while A[i] > k

6,          A[i+1] = A[i]

7,          i = i - 1

8,      A[i+1] = k

I also wrote a C program on paper. So far looks good to me.  Of course, the compiler is still the final judge.