Preperation

Prepare.java

class Test {
    public static void main(String[] args) {
        List<String> list1 = new ArrayList<String>();
        List<String> list2 = new ArrayList<String>();

        list1.add("preInput");
        list2.add("preInput");

        // Compute values.
        List<List<String>> list = computeValuesBasedOn(input1, input2, list1, list2);
        list1 = list.get(0);
        list2 = list.get(1);
    }

    private List<List<String>> computeValuesBasedOn(String input1, String input2, List<String> list1, List<String> list2) {
        List<String> newList1 = list1;
        List<String> newList2 = list2;

        // Add more items to the lists.

        List<List<String>> list = new ArrayList<List<String>>();
        list.add(newList1);
        list.add(newList2);

        return list;
    }
}

Prepare.m

#import <Foundation/Foundation.h>

void computeValues(NSString *input1, NSString *input2, NSMutableArray *list1, NSMutableArray *list2) {
	[list1 addObject:input1];
	[list2 addObject:input2];
}

int main(int argc, char *argv[]) {
	@autoreleasepool {
		NSMutableArray *list1 = [[NSMutableArray alloc] init];
		NSMutableArray *list2 = [[NSMutableArray alloc] init];
		
		[list1 addObject:@"preInput"];
		[list2 addObject:@"preInput"];
		
		computeValues(@"input1", @"input2", list1, list2);
	}
}