Matrix exponentiation by squaring, efficient calculation of Fibonacci numbers with matrices. To calculate F n for large values of n, it suffices to calculate ϕ n and then do some constant time O (1) bookkeeping, like so: Attention reader! This is really cool because it shows how the matrix algorithm … Length of array P = number of elements in P ∴length (p)= 5 From step 3 Follow the steps in Algorithm in Sequence According to Step 1 of Algorithm Matrix-Chain-Order Step 1: n ← length [p]-1 Where n is the total number of elements And length [p] = 5 ∴ n = 5 - 1 = 4 n = 4 Now we construct two tables m and s. Base case of dp are dp[1]=0 as first element of fibonnaci sequence is 0 and d[1]=1 as the second element of fibonnaci sequence is 1. The complexity of this algorithm is the number of nodes of the tree, which is … For help with Python, Unix or anything Computer Science, book a time with me on EXL skills, The Limit of Logic and The Rise of The Computer, Linear Regression as Maximum Likelihood Estimation, Linear Algebra 3 | Inverse Matrix, Elimination Matrix, LU Factorization, and Permutation Matrix, How to Graph Sine, Cosine, Tangent by Hand ✍, How to calculate video data rates from specified file sizes. If we denote the number at position n as Fn, we can formally define the Fibonacci Sequence as: Fn = … In these examples I will be using the base case of f(0) = f(1) = 1.. Display only the 20 first digits and 20 last digits of each Fibonacci number. matrix first row and first column of the matrix A. We just need to store all the values in  an array. Let ( ) 1 0 n p x a x ax a= ++ + n with a n ≠0and0. f = FIBONACCI(n) generates the first n Fibonacci numbers. Following are different methods to get the nth Fibonacci number. If this was false, there would be two previous pairs $(F_{a-1},\ F_a)$ and $(F_{b-1},\ F_b)$, which, by the property of Fibonacci numbers, would also be equal. In every iteration, we have a hidden cost of O (number of digits of f i) = O (digits (f i)). What is the minimum time complexity to find n’th Fibonacci Number? Look at the time difference there! Many times in recursion we solve the sub-problems repeatedly. The next two lines, f(1) = 1; Find the sum of first n Fibonacci numbers. Method 6 (O(Log n) Time) Below is one more interesting recurrence formula that can be used to find n’th Fibonacci Number in O(Log n) time. Write a function int fib(int n) that returns Fn. Method 1 ( Use recursion ) A simple method that is a direct recursive implementation mathematical recurrence relation given above. The Fibonacci numbers are significantly used in the computational run-time study of algorithm to determine the greatest common divisor of two integers.In arithmetic, the Wythoff array is an infinite matrix of numbers resulting from the Fibonacci sequence. By Fast powering the 2x2 matrix (can be computed in \theta(log(n))), we can compute the Fibonacci numbers in \theta(log(n)) time. Lucas form Fibonacci 5. Dynamic programming is a technique to solve the recursive problems in more efficient manner. Example. It's a very poorly worded question, but you have to assume they are asking for the n th Fibonnaci number where n is provided as the parameter.. Determine the matrix for every n,$\begin{pmatrix}1&1\\1&0\end{pmatrix}^n$. It’s … Matrix Form. algorithm considers both cases of being n value as e ven and . 2 is about Fibonacci numbers and Chap. DOI: 10.16984/SAUFENBILDER.344991 Corpus ID: 191990020. We can avoid the repeated work done is method 1 by storing the Fibonacci numbers calculated so far. In this study we present a new coding/decoding algorithm using Fibonacci Q-matrices.The main idea of our method depend on dividing the message matrix into the block matrices of size 2 × 2.We use different numbered alphabet for each message, so we get a more reliable coding method. In both contexts it refers to simplifying a complicated problem by breaking it down into simpler sub-problems in a recursive manner. In addition to all the techniques listed by others, for n > 1 you can also use the golden ratio method, which is quicker than any iterative method.But as the question says 'run through the Fibonacci sequence' this may not qualify. The Fibonacci numbers, commonly denoted Fn form a sequence, called the Fibonacci sequence, i.e; each number is the sum of the two preceding ones, starting from 0 and 1. Hence 2the power, series matrix generated by px x x( )=− −+ 1, is the Fibonacci matrix. code. Write a program using matrix exponentiation to generate Fibonacci(n) for n equal to: 10, 100, 1_000, 10_000, 100_000, 1_000_000 and 10_000_000. Refer method 4 of this for details. Method 3 ( Space Optimized Method 2 ) We can optimize the space used in method 2 by storing the previous two numbers only because that is all we need to get the next Fibonacci number in series. We also have a zero (the identity matrix), so … The formula can be derived from above matrix equation. Fibonacci Identities with Matrices. Hence 2the power, series matrix generated by px x x( )=− −+ 1, is the Fibonacci matrix. 4 Chapter 2. We start with the equations f1 = f1 and f2 = f0 + f1: This is really cool because it shows how the matrix algorithm perform in almost constant time while the polynomial algorithm continues to grow. The time complexity for this algorithm turns out to be O(n), which is fairly good, considering how bad the previous one was. In these examples I will be using the base case of f(0) = f(1) = 1.. Practice Problems. Algorithms, Mathematics, Python/ By Muthu Krishnan Definition: The Fibonacci sequence is defined by the equation, where \(F(0) = 0 \), \(F(1) = 1 \) and \(F(n) = F(n-1) + F(n-2) \text{for } n \geq 2 \). Fibonacci matrix-exponentiation is a draft programming task. In other words, the number of operations to compute F(n)is proportion… f = FIBONACCI(n) generates the first n Fibonacci numbers. With this insight, we observed that the matrix of the linear map is non-diagonal, which makes repeated execution … In both contexts it refers to simplifying a complicated problem by breaking it down into simpler sub-problems in a recursive manner. Extra. Essentially, each recursive call to fib function has to compute all the previous fibonacci numbers for its own use. Also, generalisations become natural. Can we make this algorithm run even more faster? 3. see the update). One problem with this though is you need extra memory to store the terms in an array. Fibonacci is similar to a "hello world" for many functional programming languages, since it can involve paradigms like pattern matching, memoization, and bog-standard tail recursion (which is equivalent to iteration). That's cool, but how does that help with making the Fibonacci algorithm more efficient? There exist several closed-form solutions to Fibonacci sequence which gives us the false hope that there might be an \(\mathcal{O}(1)\) solution. This program performs the Fibonacci Line Search algorithm to find the maximum of a unimodal function, f(x), over an interval, a < x < b. However, this contradicts the fact that we had chosen pairs with the smallest indices, completing our proof. Matrix Multiplication Algorithm and Flowchart. Fibonacci-Zahlen sind ein Hauptthema für dynamisches Programmieren, da der traditionelle rekursive Ansatz viele Berechnungen durchführt. The Fibonacci Sequence is an infinite sequence of positive integers, starting at 0 and 1, where each succeeding element is equal to the sum of its two preceding elements. Below is a graph of the difference in time it takes for both of the algorithms: Wow! The matrix formulation is an easy way to see famous connection between the Fibonacci numbers and ϕ. Taking determinant on both sides, we get (-1)n = Fn+1Fn-1 – Fn2 Moreover, since AnAm = An+m for any square matrix A, the following identities can be derived (they are obtained form two different coefficients of the matrix product)FmFn + Fm-1Fn-1 = Fm+n-1By putting n = n+1,FmFn+1 + Fm-1Fn = Fm+nPutting m = nF2n-1 = Fn2 + Fn-12F2n = (Fn-1 + Fn+1)Fn = (2Fn-1 + Fn)Fn (Source: Wiki)To get the formula to be proved, we simply need to do the following If n is even, we can put k = n/2 If n is odd, we can put k = (n+1)/2. Chap. initial matrix M by the matrix Qp and the Fibonacci decryption algorithm(3.9) is reduced to the n-multiple multiplication of the secret message E by the inverse matrix In this study we present a new coding/decoding algorithm using Fibonacci Q-matrices.The main idea of our method depend on dividing the message matrix into the block matrices of size 2 × 2.We use different numbered alphabet for each message, so we get a more reliable coding method. In mathematical terms, the sequence Fn of Fibonacci numbers is defined by the recurrence relation. Dynamic programming is a technique to solve the recursive problems in more efficient manner. Generate Fibonacci(2 16 ), Fibonacci(2 32) and Fibonacci(2 64) using the same method or another one. As well, I will show how to use matrices to calculate the Fib Seq. Beispiel. How does this formula work? Time complexity of this solution is O(Log n) as we divide the problem to half in every recursive call. The Fibonacci Sequence is an infinite sequence of positive integers, starting at 0 and 1, where each succeeding element is equal to the sum of its two preceding elements. Fibonacci Numbers are a prime subject for dynamic programming as the traditional recursive approach makes a lot of repeated calculations. From the above equation you can see, by multiplying the special 2x2 matrix with itself n times gives Fibonacci numbers in the Anti-diagonal elements. It is pretty impressive how much faster the poly is than the recursive! 2 is about Fibonacci numbers and Chap. Fibonacci Numbers ... creates an n-by-1 matrix containing all zeros and assigns it to f. In Matlab, a matrix with only one column is a column vector and a matrix with only one row is a row vector. ( Using power of the matrix {{1,1},{1,0}} ) This another O(n) which relies on the fact that if we n times … But is there an even Faster way to do this? Fibonacci Series. This method is contributed by Chirag Agarwal.Related Articles: Large Fibonacci Numbers in JavaPlease write comments if you find the above codes/algorithms incorrect, or find other ways to solve the same problem.References: http://en.wikipedia.org/wiki/Fibonacci_number http://www.ics.uci.edu/~eppstein/161/960109.html. Chap. An algorithm to find the nth term of fibonnaci sequence in C++ Declare an array dp[n+1] which stores the values for each position element from 3 to n once of fibonnaci sequence. So, the most computed value will be fib (1) since it has to appear in all the leaf nodes of the tree shown by answer of @kqr. A Fibonacci spiral is a pattern of quarter-circles connected inside a block of squares with Fibonacci numbers written in each of the blocks. Go through Recursive definition, show how to implement algorithm in python and see how long different approaches take. Below, I timed each function and the results are printed below: Wow! Chap.4 extends to tribonacci and higher recurrences, where a 3 3 or larger matrix replaces Q. Chap.5 covers some aspects of Fibonacci, Lucas, etc modulo m. If it's linear, then the plot of n vs. running time of LinearFibonacci(n) should be a line. 1. The Algorithm Now we want to give an algorithm that will give us the entries of M p more rapidly. Let c jk, stand for thecoefficient of … The theory says that this algorithm should run in O(n) time – given the n-th Fibonacci number to find, the algorithm does a single loop up to n. Now let's verify if this algorithm is really linear in practice. edit Lets dive right in! We use cookies to ensure you have the best browsing experience on our website. Unfortunately they all turn out to be non-optimal if you want an exact solution for a large \(n\).We will use to so-called “matrix form” instead, which we will now describe in some detail. Which takes us to another interesting method using matrices. In this tutorial we will learn to find Fibonacci series using recursion. After googling, I came to know about Binet's formula but it is not appropriate for values of n>79 as it is said here. MATRIX_FIB Algorithm generates Fibonacci numbers in the . I encourage you to find a solution for that. Please let me know if you are interested in more information! Dynamic programming is both a mathematical optimization method and a computer programming method. close, link Fibonacci Numbers ... creates an n-by-1 matrix containing all zeros and assigns it to f. In Matlab, a matrix with only one column is a column vector and a matrix with only one row is a row vector. When a new Fibonacci number is defined as the predecessor a and b, then the predecessors are prepared for a new iteration: the second in the next is equal to the calculated Fibonacci number in the current cycle b=f while the first predecessor of the new cycle, in fact, the one who in the current cycle was the second predecessor: a=b. Form the sequence that is like the Fibonacci array, with tree first elements equal to: 1, 1 and 1. Also, generalisations become natural. So this is a bad implementation for nth Fibonacci number. The Fibonacci sequence is a beautiful mathematical concept, making surprise appearances in everything from seashell patterns to the Parthenon. That's cool, but how does that help with making the Fibonacci algorithm more efficient? The Fibonacci numbers are significantly used in the computational run-time study of algorithm to determine the greatest common divisor of two integers.In arithmetic, the Wythoff array is an infinite matrix of numbers resulting from the Fibonacci sequence. The number written in the bigger square is a sum of the next 2 smaller squares. The . Unfortunately, it’s hopelessly slow: It uses Θ(n) stack space and Θ(φn) arithmetic operations, where φ=5+12 (the golden ratio). Example. Let c jk, stand for thecoefficient of xj in power series expansion of ( ) 1 1 px k+ The method was developed by Richard Bellman in the 1950s and has found applications in numerous fields, from aerospace engineering to economics.. The Algorithm Now we want to give an algorithm that will give us the entries of M p more rapidly. acknowledge that you have read and understood our, GATE CS Original Papers and Official Keys, ISRO CS Original Papers and Official Keys, ISRO CS Syllabus for Scientist/Engineer Exam, Bell Numbers (Number of ways to Partition a Set), Find minimum number of coins that make a given value, Greedy Algorithm to find Minimum number of Coins, K Centers Problem | Set 1 (Greedy Approximate Algorithm), Minimum Number of Platforms Required for a Railway/Bus Station, K’th Smallest/Largest Element in Unsorted Array | Set 1, K’th Smallest/Largest Element in Unsorted Array | Set 2 (Expected Linear Time), K’th Smallest/Largest Element in Unsorted Array | Set 3 (Worst Case Linear Time), k largest(or smallest) elements in an array | added Min Heap method, Top 20 Dynamic Programming Interview Questions, http://en.wikipedia.org/wiki/Fibonacci_number, http://www.ics.uci.edu/~eppstein/161/960109.html, Check if a M-th fibonacci number divides N-th fibonacci number, Check if sum of Fibonacci elements in an Array is a Fibonacci number or not, Program to print first n Fibonacci Numbers | Set 1, Count Fibonacci numbers in given range in O(Log n) time and O(1) space, Largest subset whose all elements are Fibonacci numbers, Interesting facts about Fibonacci numbers, Print first n Fibonacci Numbers using direct formula, Generating large Fibonacci numbers using boost library, Deriving the expression of Fibonacci Numbers in terms of golden ratio, Number of ways to represent a number as sum of k fibonacci numbers, Find the GCD of N Fibonacci Numbers with given Indices, Print all combinations of balanced parentheses, Overlapping Subproblems Property in Dynamic Programming | DP-1, Travelling Salesman Problem | Set 1 (Naive and Dynamic Programming), Write a program to print all permutations of a given string, Set in C++ Standard Template Library (STL), Write Interview We can observe that this implementation does a lot of repeated work (see the following recursion tree). Since taking matrix M to the power of n seems to help with finding the (n+1) th element of the Fibonacci Sequence, we should be able to use an efficient algorithm for exponentiation to make a more efficient Fibonacci. Method 7 Another approach:(Using formula) In this method we directly implement the formula for nth term in the fibonacci series. If we denote the number at position n as F n, we can formally define the Fibonacci Sequence as: F n = o for n = 0 Below is the implementation of above idea. Fn = {[(√5 + 1)/2] ^ n} / √5 Reference: http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Fibonacci/fibFormula.html, Time Complexity: O(1) Space Complexity: O(1). Iterative version Fibonacci 2. Naively, we can directly execute the recurrence as given in the mathematical definition of the Fibonacci sequence. Ok, Now lets take a look at how each of these perform in terms of time. In both the linear and recursive method we calculated the Fibonacci numbers using our knowledge or already calculated Fibonacci numbers. Extra Space: O(n) if we consider the function call stack size, otherwise O(1). Dynamic programming is both a mathematical optimization method and a computer programming method. Algorithms to generate Fibonacci numbers: naïve recursive (exponential), bottom-up (linear), matrix exponentiation (linear or logarithmic, depending on the matrix exponentiation algorithm). Fibonacci series is defined as a sequence of numbers in which the first two numbers are 1 and 1, or 0 and 1, depending on the selected beginning point of the sequence, and each subsequent number is the sum of the previous two. The Fibonacci sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21,... Java code using For Loop 1 I'll show you that the running time of the real-life linear Fibonacci algorithm really is O (n^2) by taking into account this hidden cost of a bigint library. Fibonacci results. Since taking matrix M to the power of n seems to help with finding the (n+1) th element of the Fibonacci Sequence, we should be able to use an efficient algorithm for exponentiation to make a more efficient Fibonacci. Let's sum these hidden cost for the whole loop up to n: The Fibonacci sequence defined with matrix-exponentiation : This gives us the sequence 0,1,1,2,3,5,8,13 … called the Fibonacci Sequence. Chap.4 extends to tribonacci and higher recurrences, where a 3 3 or larger matrix replaces Q. Chap.5 covers some aspects of Fibonacci, Lucas, etc modulo m. So, in this series, the … Method 2 ( Use Dynamic Programming ) We can avoid the repeated work done is method 1 by storing the Fibonacci numbers calculated so far. If this was false, there would be two previous pairs $(F_{a-1},\ F_a)$ and $(F_{b-1},\ F_b)$, which, by the property of Fibonacci numbers, would also be equal. Take a look at the below matrix: \begin{align} \begin{bmatrix} 0 & 1 \\ 1 & 1 In this post, a general implementation of Matrix Exponentiation is discussed. by Koscica Dusko on March 6, 2014. In plain English, the n-th Fibonacci number is the sum of the prior 2. brightness_4 For example, if n = 0, then fib() should return 0. Tail recursive version Fibonacci 4. Specifically, we have noted that the Fibonacci sequence is a linear recurrence relation — it can be viewed as repeatedly applying a linear map. Abstract The Fibonacci numbers are a sequence of integers in which every number after the rst two, 0 and 1, is the sum of the two preceding numbers. Using the matrix representation for Fibonacci numbers, discussed in other answers, we get a way to go from F_n and F_m to F_{n+m} and F_{n-m} in constant time, using only plus, multiplication, minus and division (actually not! The method was developed by Richard Bellman in the 1950s and has found applications in numerous fields, from aerospace engineering to economics.. In diesen Beispielen werde ich den Basisfall von f(0) = f(1) = 1.. Hier ist ein Beispiel eines rekursiven Baums für fibonacci… Time Complexity: T(n) = T(n-1) + T(n-2) which is exponential. Using the grade-school recurrence equation fib(n)=fib(n-1)+fib(n-2), it takes 2-3 min to find the 50th term!. 1. Thats incredible how much longer the recursive algorithm takes compared to the Polynomial…. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready. Matrix Exponentiation. The next two lines, f(1) = 1; 4 Chapter 2. Following are Algorithms for Fibonacci Series 1. However, this contradicts the fact that we had chosen pairs with the smallest indices, completing our proof. Recursive version Fibonacci 3. For n > 1, it should return Fn-1 + Fn-2. Fibonacci Series. Fibonacci was an Italian mathematician who introduced this subject to European mathematics, but the similar array was mentioned even before his time. Related tasks Time Complexity: O(Logn) Extra Space: O(Logn) if we consider the function call stack size, otherwise O(1). This algorithm is substantially faster compared to recursive Fibonacci algorithm. Here is an example recursive tree for fibonacci(4), note the repeated computations: Fibonacci series is defined as a sequence of numbers in which the first two numbers are 1 and 1, or 0 and 1, depending on the selected beginning point of the sequence, and each subsequent number is the sum of the previous two. How to Implement Fibonacci Number Algorithm using C++ Example. Tweet. We can find n’th Fibonacci Number in O(Log n) time using Matrix Exponentiation. Answer: We all know the Fibonacci recurrence as F(n+1) = F(n) + F(n-1) but we can represent this in the form a matrix as shown below: Look at the matrix A = [ [ 1 1 ] [ 1 0 ] ] . Lets find out: It is possible to write the formula in terms of matricies. Many times in recursion we solve the sub-problems repeatedly. Fibonacci using matrix representation is of the form : Fibonacci Matrix. Experience. Here is an example recursive tree for fibonacci(4), note the repeated computations: Practice Problems. Let ( ) 1 0 n p x a x ax a= ++ + n with a n ≠0and0. Fibonacci is most widely known for his famous sequence of numbers: Formally the algorithm for the Fibonacci Sequence is defined by a recursive definition: Using this we can go ahead and implement the recursive definition into python: Now whenever we have an algorithm, it is always important to make sure that we ask the following questions about it: Now without getting into the nitty gritty details here, this algorithm very greedy and takes a lot of computer steps to complete. SPOJ - Euclid Algorithm Revisited; SPOJ - Fibonacci Sum Approximate n-th Fibonacci number with some approximation formula, and if you could create one on your own it would be even better. An interesting property about these numbers is that when we make squares with these widths, we get a spiral. Please write to us at contribute@geeksforgeeks.org to report any issue with the above content. Ancient Egyptian multiplication and fast matrix exponentiation are the same algorithm applied to different operations. We can do recursive multiplication to get power(M, n) in the previous method (Similar to the optimization done in this post). The program calculates the number of iterations required to insure the final interval is within the user-specified tolerance. 3 deals with Lucas and related numbers. The negatives of the fibonacci form a pretty recognizable pattern actually ^_^ $\endgroup$ – DanielV May 7 '14 at 16:30. add a comment | Not the answer you're looking for? That is − F 0 = 0 and F 1 = 1 And Fn = F n-1 + F n-2 for n > 1. The Fibonacci numbers are the numbers in the following integer sequence.0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, …….. In this tutorial we will learn to find Fibonacci series using recursion. In dynamic programming we store the solution of these sub-problems so that we do not … 3 deals with Lucas and related numbers. SPOJ - Euclid Algorithm Revisited; SPOJ - Fibonacci Sum However, iteration or tail-recursion in linear time is only the first step: more clever exponentiation runs in logarithmic time. In dynamic programming we store the solution of these sub-problems so that we do not have to … Fibonacci Operational Matrix Algorithm For Solving Differential Equations Of Lane-Emden Type @article{akmak2019FibonacciOM, title={Fibonacci Operational Matrix Algorithm For Solving Differential Equations Of Lane-Emden Type}, author={Musa Çakmak}, journal={Sakarya University Journal of Science}, year={2019}, volume={23}, … Related. Since their invention in the mid-1800s by Arthur Cayley and later by Ferdinand Georg Frobenius, matrices became an indispensable tool in various fields of mathematics and engineering disciplines.So in fact indispensable that a copy of a matrix textbook can nowadays be had at Sears (although at amazon.com the same book is a little bit cheaper.) The Fibonacci sequence is a beautiful mathematical concept, making surprise appearances in everything from seashell patterns to the Parthenon. These numbers are well known and algorithms to compute them are so easy that they are often used in introductory algorithms courses. Given a number n, print n-th Fibonacci Number. Method 4 ( Using power of the matrix {{1,1},{1,0}} ) This another O(n) which relies on the fact that if we n times multiply the matrix M = {{1,1},{1,0}} to itself (in other words calculate power(M, n )), then we get the (n+1)th Fibonacci number as the element at row and column (0, 0) in the resultant matrix.The matrix representation gives the following closed expression for the Fibonacci numbers: Method 5 ( Optimized Method 4 ) The method 4 can be optimized to work in O(Logn) time complexity. Writing code in comment? Solve the Fibonacci Numbers practice problem in Math on HackerEarth and improve your programming skills in Linear Algebra - Matrix Exponentiation. Don’t stop learning now. We use the algorithm method to investigate structures of Fibonacci and Lucas numbers. Fibonacci Spiral. Browse other questions tagged matrices fibonacci-numbers or ask your own question. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page. So lets try another way of doing this using lists that will speed things up and make it easier to calculate. Fibonacci Numbers are a prime subject for dynamic programming as the traditional recursive approach makes a lot of repeated calculations. 3. Question: Find Nth fibonacci number in O(logN) time complexity. I was wondering about how can one find the nth term of fibonacci sequence for a very large value of n say, 1000000. By using our site, you Fibonacci results. This is a tutorial to find large fibonacci numbers using matrix exponentiation, speeded up with binary exponentiation. Please use ide.geeksforgeeks.org, generate link and share the link here. If n = 1, then it should return 1. C++ Program to Find Fibonacci Numbers using Matrix Exponentiation C++ Server Side Programming Programming The Fibonacci numbers, commonly denoted Fn form a sequence, called the Fibonacci sequence, i.e; each number is the sum of the two preceding ones, starting from 0 and 1.
Inzektor Deck 2020, New Delhi Ymca Institute For Career Studies, Dip Mixes Wholesale, Cloud Smash 4, Absolute Location In A Sentence, Mcvitie's Jobs Wembley, Gof Design Patterns In Ooad, Healthy Lunch Ideas For Hockey Players, Ge Z-wave Smart Switch,