二维数组转一维数组：

    NSArray *array = @[
                       @[@"11", @"12"],
                       @[@"21", @"22"],
                       @[@"31", @"32"],
                       @[@"41", @"42"],
                       @[@"51", @"52"]];

    NSArray *tmpArray = array[0];
    NSMutableArray *secArray = [NSMutableArray arrayWithCapacity:(tmpArray.count*array.count)];
    for (NSInteger i=0; i<(tmpArray.count*array.count); i++) {
        [secArray addObject:@"0"];
    }
    
    NSInteger count = array.count;
    for (NSInteger i=0; i<secArray.count; i++) {
        secArray[i] = array[i%count][i/count];
    }
    NSLog(@"**********----%@",secArray);

结果如下：

(
    11,
    21,
    31,
    41,
    51,
    12,
    22,
    32,
    42,
    52
)

当把上面代码下方替换 就改变了排序位置

   NSInteger count = tmpArray.count;
    for (NSInteger i=0; i<secArray.count; i++) {
        secArray[i] = array[i/count][i%count];
    }

改变结果如下：

(
    11,
    12,
    21,
    22,
    31,
    32,
    41,
    42,
    51,
    52
)

二维数组倒置：

   NSArray *tmpArray = array[0];
   NSMutableArray *newArray = [NSMutableArray arrayWithCapacity:tmpArray.count];
   for (NSInteger i=0; i<tmpArray.count; i++) {
       NSMutableArray *lineArray = [NSMutableArray arrayWithCapacity:array.count];
       for (NSInteger j=0; j<array.count; j++) {
           [lineArray addObject:@"0"];
       }
       [newArray addObject:lineArray];
   }
   
   for (NSInteger i=0; i<array.count; i++) {
       for (NSInteger j=0; j<tmpArray.count; j++) {
           newArray[j][i] = array[i][j];
       }
   }
   NSLog(@"**********____%@", newArray);

结果如下：

(
    (
        11,
        21,
        31,
        41,
        51
    ),
        (
        12,
        22,
        32,
        42,
        52
    )
)

一维数组转二维数组（5*2的二维数组）

   NSArray *secArray = @[
                       @"11", @"12",
                       @"21", @"22",
                       @"31", @"32",
                       @"41", @"42",
                       @"51", @"52"
];

   NSMutableArray *transferArray = [NSMutableArray arrayWithCapacity:5];
    for (NSInteger i=0; i<5; i++) {
        NSMutableArray *tmpArray = [NSMutableArray array];
        for (NSInteger j=0; j<2; j++) {
            [tmpArray addObject:@"0"];
        }
        [transferArray addObject:tmpArray];
    }
    for (NSInteger i=0; i<secArray.count; i++) {
        transferArray[i/2][i%2] = secArray[i];
    }
    NSLog(@"**********----%@",transferArray);

   //    5*2;
   //    m = X / 2;    
   //    n = X % 2;    m、n 代表数组下标

打印结果如下：

(
    (
        11,
        12
    ),
        (
        21,
        22
    ),
        (
        31,
        32
    ),
        (
        41,
        42
    ),
        (
        51,
        52
    )
)