iOS如何实现拼图小游戏

@property(retain, nonatomic)NSMutableArray *buttonArray;
@property(retain, nonatomic)NSMutableArray *a;
@property(retain, nonatomic)NSArray        *aa;

//图片数组a，用来储存每个图片名称，并且用于后来的打乱
self.a = [NSMutableArray arrayWithObjects:@"1.jpg",@"2.jpg",@"3.jpg",@"4.jpg",@"5.jpg",@"6.jpg",@"7.jpg",@"8.jpg",@"9.jpg", nil];
//备份一个正确顺序的图片数组，用于判断游戏是否过关
self.aa = [NSArray arrayWithArray:self.a];
//重新开始按钮
UIButton *star = [[UIButton alloc] initWithFrame:CGRectMake(120, 400, 100, 40)];
[star setTitle:@"重新开始" forState:UIControlStateNormal];
[star setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
star.layer.cornerRadius = 6.6f;
star.layer.backgroundColor = [[UIColor colorWithRed:0.922 green:0.925 blue:0.929 alpha:1]CGColor];
//添加点击事件
[star addTarget:self action:@selector(kaishi) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:star];
[star release];

//铺出9个button
    self.buttonArray = [NSMutableArray array];
    NSInteger count = 0;
    NSInteger wight = 351 / 3;
    NSInteger higth = 351 / 3;
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(j * (wight+2) + 10, i * (higth + 2) + 20, wight, higth)];
            button.backgroundColor = [UIColor blackColor];
            //给每个button上图片
            [button setImage:[UIImage imageNamed:self.a[count]] forState:UIControlStateNormal];
            [self.view addSubview:button];
            //给每个button添加点击事件
            [button addTarget:self action:@selector(change:) forControlEvents:UIControlEventTouchUpInside];
            //把button放入数组
            [self.buttonArray addObject:button];
            button.tag = count;
            [button release];
            count++;
        }
}

- (void)change:(UIButton *)sender{
    NSInteger flag = 0;
    int p = 0;
    //“9.jpg”是空白的那个，打乱后，得在图片数组里找到所在下标，用flag存在来
    for (NSInteger i = 0; i < 9; i++) {
        if ([self.a[i] isEqualToString:@"9.jpg"]) {
            flag = i;
        }
    }

    //如果所点击的button的上下左右其中有一个是空白图片的话，就跟空白图片交换在图片数组的位置
    if (sender.tag - flag == 3 || sender.tag - flag == -3 || sender.tag - flag == 1 || sender.tag - flag == -1) {
        [self.a exchangeObjectAtIndex:flag withObjectAtIndex:sender.tag];
    }
    //重新给每个button上图片
    for (int i = 0; i < 9; i++) {
        [self.buttonArray[i] setImage:[UIImage imageNamed:self.a[i]] forState:UIControlStateNormal];
    }

    //判断是否拼图成功，每对应了一张图片p就加一，如果p最后等于9说明游戏通关
    for (int i = 0; i < 9 ; i++) {
        if ([self.a[i] isEqualToString:self.aa[i]]) {
            p++;
        }else{
            break;
        }
    }
    if (p == 9) {
        NSLog(@"%d",p);
        UIAlertView *a = [[UIAlertView alloc] initWithTitle:@"恭喜！" message:@"已通关" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil];
        [a show];
        [a release];
    }
}

- (void)kaishi{
//产生0到8两个随机数，通过下标交换图片数组中的两张图片
    for (int i = 0; i < 10; i++) {
        [self.a exchangeObjectAtIndex:(arc4random() % 9)
                    withObjectAtIndex:(arc4random() % 9)];
    }
    //给每个button上图片
    for (int i = 0; i < 9; i++) {
        [self.buttonArray[i] setImage:[UIImage imageNamed:self.a[i]] forState:UIControlStateNormal];
    }
}