Data commit

Task/Knuth-shuffle/Objective-C/knuth-shuffle.m

@@ -0,0 +1,22 @@
+#import <Foundation/Foundation.h>
+
+@interface NSMutableArray (KnuthShuffle)
+- (void)knuthShuffle;
+@end
+@implementation NSMutableArray (KnuthShuffle)
+- (void)knuthShuffle {
+  for (NSUInteger i = self.count-1; i > 0; i--) {
+    NSUInteger j = arc4random_uniform(i+1);
+    [self exchangeObjectAtIndex:i withObjectAtIndex:j];
+  }
+}
+@end
+
+int main() {
+  @autoreleasepool {
+    NSMutableArray *x = [NSMutableArray arrayWithObjects:@0, @1, @2, @3, @4, @5, @6, @7, @8, @9, nil];
+    [x knuthShuffle];
+    NSLog(@"%@", x);
+  }
+  return 0;
+}