ARC Objective-C中的C风格多维数组

I'm trying to implement an n x n multidimensional array of ints in Objective-C, and because using NSMutableArray seems to be too much of an overhead I decided to implement it using only C's malloc and free. My question is, is the code below correct (no memory leaks) under ARC Objective-C?I'm trying to implement an n x n multidimension