$b_e$ following figure shows an iterative$-$Mergsort algorithm. $a_1,a_2,$dots,$a_n$ is the set of to rted. Initially, each element of $a_1,a_2,$dots,$a_n$ is considered as an array separately and each ${?}^r{?}^{\text{s}\text{u}\text{e}}$ queue $Q.$ Then, removing two arrays from the front of the queue, merging Wh array at the end of the queue. The process is iteratively done until the first numbers of all arrays are com merging two arrays $($merge$),$ they are done recirse. The operation inject adds an element to the end of the con queue while eject removes and returns show states of the $Q$ at each step, in other words, show the changes of $Q(10\text{'}).$

function iterative$-$mergesort $(a[1$dotsn$])$

Input: elements $a_1,a_2,$dots,$a_{n}tobe$ sorted

$Q=[](empty$ queue$)$

for $i=1ton$ :

inject $(Q,[a_i])$

while $|Q|>1$ :

inject $(Q,$merge$(eject(Q),$eject$(Q)))$

return eject $(Q)$