我该如何编写一个函数，通过递归返回等于目标和的3个数字的所有组合

def three_sum(nums, target):
    def backtrack(start, target, path):
        if len(path) == 3:
            if sum(path) == target:
                result.append(path[:])
            return
        for i in range(start, len(nums)):
            if i > start and nums[i] == nums[i - 1]:
                continue
            if sum(path) + nums[i] > target:
                break
            path.append(nums[i])
            backtrack(i + 1, target, path)
            path.pop()

    result = []
    nums.sort()
    backtrack(0, target, [])
    return result

# 示例
nums = [-1, 0, 1, 2, -1, -4]
target = 0
print(three_sum(nums, target))