algorithm - 网格中的随机数

Question

我的应用程序 View 显示 16 个数字的网格。每次按下按钮时，我都希望数字的排列发生变化，并且每次都是随机的。该应用程序通过 16 个小的 UIImageView 来工作，每个 UIImageView 都有一个与之关联的图像(数字)。目前，我通过生成随机数并使该数字对应于特定排列来“随机化”排列。像这样:

int  number = rand() % 7;

if (number == 1) {
    space1.image = three;
    space2.image = ten;
    space3.image = one;
    space4.image = eight;
    space5.image = two;
    space6.image = five;
    space7.image = thirteen;
    space8.image = six;
    space9.image = four;
    space10.image = fifteen;
    space11.image = sixteen;
    space12.image = nine;
    space13.image = fourteen;
    space14.image = eleven;
    space15.image = twelve;
    space16.image = seven;
}
else if (number == 2) {
    space1.image = ten;
    ................
    .............etc

显然有数百万种可能的安排，我在这里只捕获了其中的 7 种。谁能建议一种真正随机化安排的方法？

希望我已经说得够清楚了。在此先感谢您的帮助。

乔治

Answer 1

不是制作 16 个相同的实例变量，而是将 UIImageView 对象存储在一个数组中，将 UIImage 对象存储在一个可变数组中，并随机化图像数组的元素:

NSMutableArray *imageViews, *images;

imageViews = [[NSMutableArray alloc] init];
images = [[NSMutableArray alloc] init];

for (int i = 0; i < 16; i++) {
    UImageView *imageView = [[UIImageView alloc] initWithFrame:someFrame];
    [imageViews addObject:imageView];
    [imageView release];

    UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"image_%d"], i];
    [images addObject:image];        
}

- (void)randomize
{
    for (int i = 0; i < 100; i++) {
        int idx1 = arc4random() % images.count;
        int idx2 = arc4random() % images.count;
        [images exchangeObjectAtIndex:idx1 withObjectAtIndex:idx2];
    }

    for (int i = 0; i < imagesViews.count) {
        [[imageViews objectAtIndex:i] setImage:[images objectAtIndex:i]];
    }
}