2有一个数组,数组中有13个元素,先将该数组进行分组,每3个元素为一组,分为若干组,最后用一个数组统一管理这些分组.(要动态创建数组).

NSMutableArray *arr = [[NSMutableArray alloc] init];
for (int i = 0; i < 15 ; i++) {
[arr addObject:[NSString stringWithFormat:@"damo%d",i]];
}
NSLog(@"%@",arr);
NSMutableArray *bigArr =  [[NSMutableArray alloc] initWithCapacity:1];
NSMutableArray *smallArr = nil;
for (int i = 0; i < [arr count]; i++) {
if (i % 3 == 0) {
//只要读到0 3 6 9 12 就开辟空间存储接下来的三个元素
smallArr = [[NSMutableArray alloc] initWithCapacity:1];
//将小数组添加到大数组中进行管理
[bigArr addObject:smallArr];
}
[smallArr addObject:[arr objectAtIndex:i]];
}
NSLog(@"%@",bigArr);</span>