How to transpose a matrix in Objective c?

Question

i have a 2d matrix. how can i transpose it in objective c?

have i use nested loop to transpose it as i failed to find any method in array and mutablearray classes.

My matix is of 3x3.

NSMutableArray *row1=[NSMutableArray arrayWithObjects:@1,@2,@3, nil];
NSMutableArray *row2=[NSMutableArray arrayWithObjects:@4,@5,@6, nil];
NSMutableArray *row3=[NSMutableArray arrayWithObjects:@7,@8,@9, nil];

NSMutableArray *twoDArray=[NSMutableArray arrayWithObjects:row1,row2,row3, nil];
NSLog(@"%@",twoDArray);

what to do after this?

Answer 1

It's easy as that:

NSMutableArray *result = [NSMutableArray arrayWithCapacity:3];

for (NSUInteger i = 0; i < 3; i++) {
    [result addObject:@[row1[i], row2[i], row3[i]]];
}

I assumed it will always be 3x3 matrix, for simplicity.