对按时间先后顺序的列表按同一天进行分组

实现代码：

- (NSMutableArray *)reGroupDataSoure:(NSArray *)originArr{    NSDateFormatter *dateFmt = [[NSDateFormatter alloc] init];    [dateFmt setDateFormat:@"yyyy-MM-dd"];    NSMutableArray *groupsArr = [NSMutableArray new];    int i = 0;    int j;    for (;i < [originArr count] - 1;) {        NSMutableArray *sameArr = [NSMutableArray new];        NSDictionary *dic = [originArr objectAtIndex:i];        [sameArr addObject:dic];        long long ct = [[dic objectForKey:@"ct"] longLongValue];        NSDate *ctDate = [NSDate dateWithTimeIntervalSince1970:ct/1000];        NSString *ctString = [dateFmt stringFromDate:ctDate];        //NSLog(@"day -- %@",ctString);        j = i + 1;         if (j == [originArr count]) {            if (j == 1) {                //只有一个元素时                [groupsArr addObject:originArr];            }            return groupsArr;        }        for (; j < [originArr count];) {            NSDictionary *jDic = [originArr objectAtIndex:j];            long long jct = [[jDic objectForKey:@"ct"] longLongValue];            NSDate *jctDate = [NSDate dateWithTimeIntervalSince1970:jct/1000];            NSString *jctString = [dateFmt stringFromDate:jctDate];            if ([jctString isEqualToString:ctString]) {                //同一组                [sameArr addObject:jDic];                j++;                if (j == [originArr count]) {                    [groupsArr addObject:sameArr];                    return groupsArr;                }            }            else            {                i = j;                [groupsArr addObject:sameArr];                 if(i == [originArr count] - 1)                {                    //最后一个跟倒数第二个不同组                    [groupsArr addObject:@[jDic]];                      return groupsArr;                }                break;            }        }    }    return groupsArr;}