Question

我正在尝试完成1个练习，但是我自己找不到解决方案。我得到一个数字，函数应该使用递归来查找值：

if n == 1: return 1
elif n != 1: fun(n-1) + n

但是我想向我的函数提供2个值，即起点和终点，而我的函数会找到范围内的所有值（起点，终点）。

Answer 1

使用两个参数定义函数。当您进行递归调用时，其中一个会减少，而另一个保持不变：

import pygame

white = (255, 255, 255)
black = (0, 0, 0)

class Game():
    width = 800
    height = 600
    screen = pygame.display.set_mode((width, height))
    def __init__(self):
        pass
    def fill_screen(self, color):
        self.color = color
        self.screen.fill(self.color)

class Player(pygame.sprite.Sprite):
    lead_x = 800/2
    lead_y = 600/2
    velocity = 0.002
    block_size = 10
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.draw.rect(game.screen, black, [self.lead_x, self.lead_y, self.block_size, self.block_size])

    def move_player_x_left(self):
        self.lead_x += -self.velocity

    def move_player_x_right(self):
        self.lead_x += self.velocity

    def move_player_y_up(self):
        self.lead_y += -self.velocity

    def move_player_y_down(self):
        self.lead_y += self.velocity

game = Game()
player = Player()

exitGame = False
while not exitGame:
    game.fill_screen(white)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            exitGame = True
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_w:
                player.move_player_y_up()
            if event.key == pygame.K_s:
                player.move_player_y_down()
            if event.key == pygame.K_d:
                player.move_player_x_right()
            if event.key == pygame.K_a:
                player.move_player_x_left()
    pygame.display.update()
pygame.quit()
quit()

别忘了，当您进行递归调用时，必须返回结果。

Python，范围（a，b）中的递归

1 个答案: