Data commit

Task/Mutual-recursion/Objective-C/mutual-recursion.m

@@ -0,0 +1,34 @@
+#import <Foundation/Foundation.h>
+
+@interface Hofstadter : NSObject
++ (int)M: (int)n;
++ (int)F: (int)n;
+@end
+
+@implementation Hofstadter
++ (int)M: (int)n
+{
+  if ( n == 0 ) return 0;
+  return n - [self F: [self M: (n-1)]];
+}
++ (int)F: (int)n
+{
+  if ( n == 0 ) return 1;
+  return n - [self M: [self F: (n-1)]];
+}
+@end
+
+int main()
+{
+  int i;
+
+  for(i=0; i < 20; i++) {
+    printf("%3d ", [Hofstadter F: i]);
+  }
+  printf("\n");
+  for(i=0; i < 20; i++) {
+    printf("%3d ", [Hofstadter M: i]);
+  }
+  printf("\n");
+  return 0;
+}