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. 2023 Aug 23;23(17):7364. doi: 10.3390/s23177364
Algorithm 1 The process of pruning tree construction
Input: postfix form of the logical expression pfix; empty stack stack; the value of the node value; child node children; the number of nodes in the subtree num_children; parent node parent
Output: pruning tree
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    Class ExpTree: //Constructing nodes in an expression tree

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     procedure add_child(children): //Adding child nodes to a subtree

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      if children is a list then: //The children is a list

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       for each ch in children do:

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        ch.parent ← this //Set the current node (this) to be the parent of the child ch

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       end for

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       append children to this.children

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      else: //The children is just a node

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       children.parent ← this //Set the current node (this) to be the parent of children

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       append children to this.children

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    procedure constructTree(pfix):

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     for i from length of pfix −1 to 0 step −1 do //Iterate over pfix in reverse order

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      if isOperand(pfix[i]) then //pfix[i] is the operand

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       node ← new ExpTree(pfix[i]) //Use pfix[i] to create a new ExpTree node

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       push node to stack

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      else: //pfix[i] is the operator

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       v1 ← pop from stack //v1 is the current operand or subtree

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       v2 ← pop from stack //v2 is the subtree generated in the previous loop

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       nn ←new ExpTree(pfix[i]) //nn is the root node

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       if v1.value == pfix[i] then //v1 is equal to the current operator pfix[i]

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        nn.add_child(v1.children) //Constructing the pruning tree

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       else:

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        nn.add_child(v1)

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       if v2.value == pfix[i] then //pfix[i] is equal to the operator of subtree v2

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        nn.add_child(v2.children) //Constructing the pruning tree

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       else:

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        nn.add_child(v2)

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       push nn to stack

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     end for

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    return purning tree ← pop from stack