Algorithm 2 Selecting a Similar Set Based on Energy Cost

Input: States s Output: Similar set $S_{ene}$ of s   1: Create a empty stack   2: while $s\ne \varnothing$ do   3:    a is the action that pops from the head of state s   4:    if $a=e$ then   5:        Clear the stack   6:    else   7:        Push a to the stack   8:    end if   9: end while 10: Measure the length of the $stack$ and mark it as l 11: $S_{ene}=\varnothing$ 12: $S^{\prime }=S_{pa}$ 13: while $\left|S^{\prime }\right|\ge \theta ·\left|S_{pa}\right|$  do 14:    Select $s^{\prime }$ from $S^{\prime }$ 15:    $l^{\prime }=$ executing Line 1 to Line 10 with $s^{\prime }$ 16:    if $l^{\prime }=l$ then 17:        $S_{ene}=S_{ene}\cup \left\{s^{\prime }\right\}$ 18:        $S^{\prime }=S^{\prime }\setminus \left\{s^{\prime }\right\}$ 19:    else 20:        $S^{\prime }=S^{\prime }\setminus \left\{s^{\prime }\right\}$ 21:    end if 22: end while 23: Return $S_{ene}$