Data commit

Task/Anonymous-recursion/Objective-C/anonymous-recursion-1.m

@@ -0,0 +1,32 @@
+#import <Foundation/Foundation.h>
+
+@interface AnonymousRecursion : NSObject { }
+- (NSNumber *)fibonacci:(NSNumber *)n;
+@end
+
+@implementation AnonymousRecursion
+- (NSNumber *)fibonacci:(NSNumber *)n {
+  int i = [n intValue];
+  if (i < 0)
+    @throw [NSException exceptionWithName:NSInvalidArgumentException
+                                 reason:@"fibonacci: no negative numbers"
+                               userInfo:nil];
+  int result;
+  if (i < 2)
+    result = 1;
+  else
+    result = [[self performSelector:_cmd withObject:@(i-1)] intValue]
+           + [[self performSelector:_cmd withObject:@(i-2)] intValue];
+  return @(result);
+}
+@end
+
+int main (int argc, const char *argv[]) {
+  @autoreleasepool {
+
+    AnonymousRecursion *dummy = [[AnonymousRecursion alloc] init];
+    NSLog(@"%@", [dummy fibonacci:@8]);
+
+  }
+  return 0;
+}

Task/Anonymous-recursion/Objective-C/anonymous-recursion-2.m

@@ -0,0 +1,26 @@
+#import <Foundation/Foundation.h>
+
+int fib(int n) {
+    if (n < 0)
+        @throw [NSException exceptionWithName:NSInvalidArgumentException
+                                 reason:@"fib: no negative numbers"
+                               userInfo:nil];
+    int (^f)(int);
+    __block __weak int (^weak_f)(int); // block cannot capture strong reference to itself
+    weak_f = f = ^(int n) {
+        if (n < 2)
+            return 1;
+        else
+            return weak_f(n-1) + weak_f(n-2);
+    };
+    return f(n);
+}
+
+int main (int argc, const char *argv[]) {
+  @autoreleasepool {
+
+    NSLog(@"%d", fib(8));
+
+  }
+  return 0;
+}

Task/Anonymous-recursion/Objective-C/anonymous-recursion-3.m

@@ -0,0 +1,25 @@
+#import <Foundation/Foundation.h>
+
+int fib(int n) {
+    if (n < 0)
+        @throw [NSException exceptionWithName:NSInvalidArgumentException
+                                 reason:@"fib: no negative numbers"
+                               userInfo:nil];
+    __block int (^f)(int);
+    f = ^(int n) {
+        if (n < 2)
+            return 1;
+        else
+            return f(n-1) + f(n-2);
+    };
+    return f(n);
+}
+
+int main (int argc, const char *argv[]) {
+  @autoreleasepool {
+
+    NSLog(@"%d", fib(8));
+
+  }
+  return 0;
+}