符号运算

from sympy import cse

def simplify_and_generate_cpp_code(expr, function_name="simplified_function"):
    # 提取出表达式中的重复子表达式
    sub_exprs, simplified_expr = cse(expr)

    # 构建 C++ 代码字符串
    cpp_code = "#include <cmath>\n\n"
    cpp_code += "double " + function_name + "("

    # 添加函数参数
    for i, (var, _) in enumerate(sub_exprs):
        cpp_code += f"double {var}"
        if i < len(sub_exprs) - 1:
            cpp_code += ", "
    cpp_code += ") {\n"

    # 添加局部变量定义和初始化
    for var, sub_expr_var in sub_exprs:
        cpp_code += f"    double {str(var)};\n"
    cpp_code += "\n"

    # 添加表达式赋值
    for var, sub_expr in sub_exprs:
        cpp_code += f"    double {str(sub_expr[0])} = {str(sub_expr[1])};\n"

    # 添加返回语句
    cpp_code += f"    return {simplified_expr};\n"
    cpp_code += "}\n"

    with open('funcpp.py', 'w') as file:
        file.write(cpp_code)


# 示例使用
from sympy import symbols, sin, cos

# 定义一个复杂的表达式
x, y = symbols('x y')
expr = x+y+y * (x**2*(x+y))

# 调用函数进行化简并生成 Python 函数
simplified_function = simplify_and_generate_cpp_code(expr)