Below is the pseudo code of Count Sort. The indexes are $0-$based for the array $"$C$",$ but $1-$based for arrays $"A"$ and $"B".$ The algorithm is stable. However, if we change the last loop to go from $1$ upto A$.$length instead of A$.$length down to $1,$ it no longer remains stable.

Modify the code below, so that if we go from $1$ up to A$.$length, it still remains stable having asymptotic time complexity of $O(n+k).$

Count Sort $(A,B,C)$

$\frac{\frac{?}{?}}{?}$ let $C[0..k]$ be a new array

for $i=0$ to $k$

$C[i]=0$;

for $j=1$ to A$.$length

$C[A[j]]=C[A[j]]+1$;

For $i=1$ to $k$

$C[i]=C[i]+C[i-1]$

For $j=A.$length to $1$

$B[C[A[j]]]=A[j]$

$C[A[j]]=C[A[j]]-1$;