字符串中多项式系数的解析

def parse_polynomial_coefficients(string):
    coefficients = []
    current_coefficient = ""
    current_sign = 1

    for char in string:
        if char.isdigit():
            current_coefficient += char
        elif char == '+':
            if current_coefficient:
                coefficients.append(current_sign * int(current_coefficient))
                current_coefficient = ""
            current_sign = 1
        elif char == '-':
            if current_coefficient:
                coefficients.append(current_sign * int(current_coefficient))
                current_coefficient = ""
            current_sign = -1
        elif char.isalpha():
            # Handle exponent if needed
            pass

    if current_coefficient:
        coefficients.append(current_sign * int(current_coefficient))

    return coefficients

# 示例用法
string = "2x^3 + 5x^2 - 3x + 1"
coefficients = parse_polynomial_coefficients(string)
print(coefficients)  # 输出：[2, 5, -3, 1]