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.(动态开辟)

NSMutableArray *arr = [[NSMutableArray alloc] init];
for (int i = 0; i < 13; i++) {
[arr addObject:[NSString stringWithFormat:@"hehe%d", i + 1]];
}
NSLog(@"%@", arr);
//分组initWithCapacity初始化一个容器.

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];
//将小数组添加加到大数组中进行管理
[bigArr addObject:smallArr];
}
[smallArr addObject:[arr objectAtIndex:i]];
}
NSLog(@"%@", bigArr);