Question $1(4$ points$)$

Consider the following backtracking algorithm for generating all permutation of an array of numbers:

Permute $,$ a$)$

if $n=i$

print a

else

for $)=1$;$1(n$;$1++$

swap $a[1]$ and $a[n]$

Permute $($n$-1,$ a$)$

swap $a[i]$ and $a[n]$

Now suppose the function is invoked as follows:

$a[1]=7$

$a[2]=8$

$a[3]=9$

Permute $,$ a$)$

Specify the order beside each number below matching the order in which they will be printed by the above algorithm.

$879$

$798$

$897$