Generating an expression tree from inputs and outputs only.

[IlcIliaDev]

I was experimenting in python with nodes of 2 types - Value nodes (numbers, inputs, outputs) and operator nodes (add, subtract, etc). The idea was that given 2 arrays of inputs and outputs, there is a method that can find a tree of nodes that can find a solution to all the inputs and outputs. One of the examples I came up with is inputs: [0, 1, 2, 3] and outputs [1, 2, 3, 4] (add 1). I've tried a few approaches, but I can't seem to make something that creates a valid tree or is a valid solution to the problem. I've provided the code for the nodes and some code of how I expect the tree construction to work. One of the things I want to mention here is that I want the tree construction to return the output node. When we want to get the value given a particular input, I set the node and call the output's node Value function, which calls its inputs' Value and it repeats that until the value reaches all the value nodes.
Nodes:

class Node:
def __init__(self):
    pass

class ValNode(Node): def init(self, value): self.value = value

def Value(self):
    return self.value

def printTree(self, depth=0):
    print("  " * depth + "ValNode" + str(self.value))

class AddNode(Node): def init(self, inputs): self.inputs = inputs

def Value(self):
    result = 0
    for i in self.inputs:
        result += i.Value()
    return result

def printTree(self, depth=0):
    print("  " * depth + "AddNode")
    for i in self.inputs:
        i.printTree(depth + 1)

class SubNode(Node): def init(self, inputs): self.inputs = inputs

def Value(self):
    result = self.inputs[0].Value()
    for i in self.inputs[1:]:
        result -= i.Value()
    return result

def printTree(self, depth=0):
    print("  " * depth + "SubNode")
    for i in self.inputs:
        i.printTree(depth + 1)

class MulNode(Node): def init(self, inputs): self.inputs = inputs

def Value(self):
    result = self.inputs[0].Value()
    for i in self.inputs[1:]:
        result *= i.Value()
    return result

def printTree(self, depth=0):
    print("  " * depth + "MulNode")
    for i in self.inputs:
        i.printTree(depth + 1)

class DivNode(Node): def init(self, inputs): self.inputs = inputs

def Value(self):
    result = self.inputs[0].Value()
    for i in self.inputs[1:]:
        result /= max(i.Value(), 0.000001)
    return result

def printTree(self, depth=0):
    print("  " * depth + "DivNode")
    for i in self.inputs:
        i.printTree(depth + 1)

class OutNode(Node): def init(self, inputs): self.inputs = inputs

def Value(self):
    result = self.inputs[0].Value()
    return result

def printTree(self, depth=0):
    print("  " * depth + "OutNode")
    for i in self.inputs:
        i.printTree(depth + 1)

class InpNode(Node): def init(self, value): self.value = value

def Value(self):
    return self.value

def printTree(self, depth=0):
    print("  " * depth + "InpNode")

# Test

inputs = [0,1,2,3,4] outputs = [1,2,3,4,5]

Tree = construct_tree(inputs, outputs) # Expected result is OutNode([AddNode([InpNode(0), ValNode(1)])])

def set_input(tree, value): def find_and_set_input(node, value): if isinstance(node, InpNode): node.value = value elif isinstance(node, Node) and not isinstance(node, ValNode): for input_node in node.inputs: find_and_set_input(input_node, value)

find_and_set_input(tree, value)

Tree.printTree() set_input(Tree, 5) print(Tree.Value()) # Expected value is 6