I'm trying to make bubble sort using Cocoa classes, but I've found some problems. here is the code:
#import <Foundation/Foundation.h>
int main (int argc, const char * argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
NSMutableArray *array=[[NSMutableArray alloc] init];
int a,b;
for (int i=0;i<10;i++) {
int newElement=rand()%100;
[array addObject:[NSString stringWithFormat:@"%d",newElement]];
NSLog(@"%i %@",i,[array objectAtIndex:i]);
}
[array addObject:[NSNull null]];
/*for (int a=1;a<10;a++){ */
//===Problem exact in this place
for (int i=9;i>=1;i--) {
NSNumber *tmp1=[array objectAtIndex:i]; //9
NSNumber *tmp2=[array objectAtIndex:i-1]; //8
if ([[array objectAtIndex:i] compare:[array objectAtIndex:i-1]]==NSOrderedAscending) { //if ([obj1 integerValue] > [obj2 integerValue]) this is -NSOrderedDescending;
[tmp1 retain];
[array replaceObjectAtIndex:i-1 withObject:tmp1];
[array replaceObjectAtIndex:i withObject:tmp2];
[tmp1 release];
}
}
`NSLog(@"\n==SORTED==\n");
for (int i=0;i<10;i++) NSLog(@"%i %@",i,[array objectAtIndex:i]);`
So in output in terminal i see this:
==UNSORTED==
7
49
73
58
30
72
44
78
23
9
==SORTED==
23
7
49
73
58
30
72
44
78
9
I cant' understand why does it not start from index 9? As I can see it start sorting from index 8 (taking integer 23) and goes to index 1. But when he meets integer 7 at index 1 why it replaces by integer 23, it's not corresponds to the condition of a circle for()???.. Also exact the same algorithm on C++ without classes and OOP stuff works great, so I guess an algorithm is correct there. Please guys help understand this, I spent a half of a day on it :)) Thanks a lot in advance for the answers.