Recursion in Objective-C

Recursive.m

- (BOOL)isPowerOfTwo:(NSUInteger)number {
    if(number == 0) return NO;
    if(number == 1 || number == 2) return YES;
    return [self findPower:number accumulator:2];
}

- (BOOL)findPower:(NSUInteger)n accumulator:(NSUInteger)accumulator {
    if(accumulator == n) return YES;
    if(accumulator > n) return NO;
    return [self findPower:n accumulator:(2 * accumulator)];
}

- (NSUInteger)lengthOfArraysSuffix:(NSArray *)one two:(NSArray *)two {
    return [self lengthOfArraysSuffix:one two:two accumulator:0 equal:YES];
}

- (NSUInteger)lengthOfArraysSuffix:(NSArray *)one two:(NSArray *)two accumulator:(NSUInteger)acc equal:(BOOL)equal {
    if(one.count == 0 || two.count == 0 || !equal) return acc;
    id object1 = [one lastObject];
    id object2 = [two lastObject];
    BOOL isEqual = [object1 compare:object2] == NSOrderedSame;
    NSArray *subArrayOne = [one subarrayWithRange:NSMakeRange(0, one.count - 1)];
    NSArray *subArrayTwo = [two subarrayWithRange:NSMakeRange(0, two.count - 1)];
    NSUInteger newAccumulator = isEqual ? acc + 1 : acc + 0;
    return [self lengthOfArraysSuffix:subArrayOne two:subArrayTwo accumulator:newAccumulator equal:isEqual];
}