Fisher-yates implementation in Objective-C

intoxicated · intoxicated · commit 88b293301593 · 2014-01-04T16:32:03.000-05:00
diff --git a/Fisher-Yates/Obj-C/intoxicated/Fisher-yates.h b/Fisher-Yates/Obj-C/intoxicated/Fisher-yates.h
@@ -0,0 +1,15 @@
+//
+//  Fisher-yates.h
+//  Algorithms
+//
+//  Created by intoxicated on 1/4/14.
+//  Copyright (c) 2014 intoxicated. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface Fisher_yates : NSObject
+
++ (void)shuffle:(NSMutableArray *)array;
+
+@end
diff --git a/Fisher-Yates/Obj-C/intoxicated/Fisher-yates.m b/Fisher-Yates/Obj-C/intoxicated/Fisher-yates.m
@@ -0,0 +1,28 @@
+//
+//  Fisher-yates.m
+//  Algorithms
+//
+//  Created by intoxicated on 1/4/14.
+//  Copyright (c) 2014 intoxicated. All rights reserved.
+//
+
+#import "Fisher-yates.h"
+
+@implementation Fisher_yates
+
++ (void)shuffle:(NSMutableArray *)array
+{
+    int swapIndex;
+    id temp;
+    
+    for(int i = (int)array.count - 1; i > 0; --i)
+    {
+        swapIndex = arc4random() % i;
+        
+        temp = [array objectAtIndex:i];
+        [array replaceObjectAtIndex:i withObject:[array objectAtIndex:swapIndex]];
+        [array replaceObjectAtIndex:swapIndex withObject:temp];
+    }
+}
+
+@end
diff --git a/Fisher-Yates/Obj-C/intoxicated/Fisher-yates_test.m b/Fisher-Yates/Obj-C/intoxicated/Fisher-yates_test.m
@@ -0,0 +1,29 @@
+//
+//  Fisher-Yates_test.m
+//  Fisher-Yates
+//
+//  Created by intoxicated on 1/4/14.
+//  Copyright (c) 2014 intoxicated. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+#import "Fisher-yates.h"
+
+int main(int argc, const char * argv[])
+{
+
+    @autoreleasepool {
+        
+        NSMutableArray * array = [[NSMutableArray alloc] init];
+        
+        for (NSInteger i = 0; i < 10; i++)
+            [array addObject:[NSNumber numberWithInteger:i]];
+        
+        [Fisher_yates shuffle:array];
+        
+        NSLog(@"Shuffle result: %@", array);
+
+    }
+    return 0;
+}
+
