如何阻止pygame圈子重叠？

import pygame
import random

pygame.init()

# 定义圈子类
class Circle:
    def __init__(self, x, y, radius):
        self.x = x
        self.y = y
        self.radius = radius

    def draw(self):
        pygame.draw.circle(screen, (255, 0, 0), (self.x, self.y), self.radius)

# 创建圈子列表
circles = []

# 创建屏幕
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Circle Overlap")

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # 创建新圈子
    x = random.randint(0, 800)
    y = random.randint(0, 600)
    radius = random.randint(10, 50)
    new_circle = Circle(x, y, radius)

    # 检查新圈子与已存在的圈子是否重叠
    overlap = False
    for circle in circles:
        distance = ((circle.x - new_circle.x) ** 2 + (circle.y - new_circle.y) ** 2) ** 0.5
        if distance < circle.radius + new_circle.radius:
            overlap = True
            break

    # 如果重叠，则重新生成新圈子的位置或半径
    if overlap:
        continue

    # 将新圈子添加到圈子列表中
    circles.append(new_circle)

    # 清空屏幕
    screen.fill((255, 255, 255))

    # 更新和绘制所有的圈子
    for circle in circles:
        circle.draw()

    # 刷新屏幕
    pygame.display.flip()

pygame.quit()