simple_solver_recursive.py

# Simple solver
import os
os.system("clear")

print("Simple Solver")
print("Enter a problem in the following format using integers only: ")
print("1 2 3 == 7")
print("Type q to quit")

def solver(x, y, z, answer, o1 = "+", o2 = "+"):
    # Define list of possible operators
    operations = ["+", "-", "*", "/", "%"]

    # Base case
    equation = "{} {} {} {} {}".format(x, o1, y, o2, z)
    if eval(equation) == answer:
        print("\n{} = {}".format(equation, answer))
        return True

    if o1 == "%" and o2 == "%":
        return False

    # Next operation
    if o2 == "%":
        o1 = operations[operations.index(o1) + 1]
        o2 = "+"
    else:
        o2 = operations[operations.index(o2) + 1]

    return solver(x, y, z, answer, o1, o2)

while True:
    # Get the problem from the user
    problem = input("\n> ")

    # Split into tokens
    tokens = problem.split()

    if tokens[0] == "q":
        break

    try:
        # Convert to integers
        x = int(tokens[0])
        y = int(tokens[1])
        z = int(tokens[2])
        answer = int(tokens[-1])
    except:
        print("Invalid input")
        continue

    solution_found = solver(x, y, z, answer)

    # Check if solution not found
    if not solution_found:
        print("No solution found")

print("\nThe end")