Question

I’m trying to create a sorted array but im having trouble understanding how I would created it.
I have a string (s1) and another array (a1,a2,a3,….).

I want to create a new array using the string and array. I would like to put them in this order (s1 – ar – s1 – ar – s1 -ar).

*ar = the original array in a random order.

How would I go about that creating this array?

Thanks for any help

*Edit: I would like a shuffled array having s1 string at every alternate index

Answer 1

I ended up shuffling the array and adding the string to every even index.

NSMutableArray *array = [NSMutableArray arrayWithObjects:@"a1", @"a2", @"a3", @"a4", @"a5",nil];

[array shuffle];
for (int i = 0 ; i<array.count; i=i+2) {
    [array insertObject:@"s1" atIndex:i];
}

NSLog(@"%@",array);

This is how I shuffled the array

NSMutableArray+Shuffling.h

    @interface NSMutableArray (Shuffling)
    - (void)shuffle;
    @end 


NSMutableArray+Shuffling.m
#import "NSMutableArray+Shuffling.h"

@implementation NSMutableArray (Shuffling)

- (void)shuffle
{
    for (uint i = 0; i < self.count; ++i)
    {
        // Select a random element between i and end of array to swap with.
        int nElements = self.count - i;
        int n = arc4random_uniform(nElements) + i;
        [self exchangeObjectAtIndex:i withObjectAtIndex:n];
    }
}
@end

This I what the output looked like
Array (s1,
a3,
s1,
a5,
s1,
a4,
s1,
a2,
s1,
a1)

Sorry If the question was poorly worded.