Question

Probability = 0.52;
SharePrice = 215;
n = 10000;
count = 0;
count250 = 0;
count200 = 0;

for i = 1:n
    CoinToss = rand(1);
    if (SharePrice == 200)
        break;
    end
     if (SharePrice == 250)     
        break;
    end
    if(Probability < CoinToss)
        SharePrice = SharePrice - 0.2;        
    else
        SharePrice = SharePrice + 0.2;        
    end  
end

代码似乎超出了我给出的限制（200和250），为什么它不会停止？

Answer 1

欢迎浮点不准确;您的handle_event可能最多不能合计200，因此它最终会导致import pygame as pg from pygame.math import Vector2 class Player(pg.sprite.Sprite): def __init__(self, pos, *groups): super().__init__(*groups) self.image = pg.Surface((30, 50)) self.image.fill(pg.Color('steelblue2')) self.rect = self.image.get_rect(center=pos) self.vel = Vector2(0, 0) self.pos = Vector2(pos) def update(self): self.pos += self.vel self.rect.center = self.pos class Bullet(pg.sprite.Sprite): def __init__(self, pos, velocity): super().__init__() self.image = pg.Surface((5, 5)) self.image.fill(pg.Color('aquamarine1')) self.rect = self.image.get_rect(center=pos) self.pos = pos self.vel = velocity def update(self): self.pos += self.vel self.rect.center = self.pos def main(): screen = pg.display.set_mode((640, 480)) clock = pg.time.Clock() all_sprites = pg.sprite.Group() bullets = pg.sprite.Group() player = Player((100, 300), all_sprites) done = False while not done: for event in pg.event.get(): if event.type == pg.QUIT: done = True elif event.type == pg.KEYDOWN: if event.key == pg.K_d: player.vel.x = 5 elif event.key == pg.K_SPACE: # Just create a bullet and add it to the sprite groups. bullet = Bullet(player.rect.center, Vector2(8, 0)) bullets.add(bullet) all_sprites.add(bullet) elif event.type == pg.KEYUP: if event.key == pg.K_d: player.vel.x = 0 all_sprites.update() screen.fill((30, 30, 30)) all_sprites.draw(screen) pg.display.flip() clock.tick(30) if __name__ == '__main__': pg.init() main() pg.quit()条件失败（同样适用于SharePrice）。

如果SharePrice == 200低于200或高于250，您应该考虑SharePrice == 250离开循环：

break

Break语句不会执行

1 个答案: