Finding a particular Fibonacci number is easy: given F(1) = F(2) = 1, one can build successively bigger values with the recurrence F(n) = F(n-1) + F(n-2). The problem is that lots of computation is repeated using this method. One approach is to *store* the results of previous computation. We can store previously-computed Fibonacci numbers in a global array of integers that we have allocated. Filling in an array with sentinel values of zero will let you check if that value has been computed already. If, for example, F(x) is non-zero then that value has already been computed and you can return that partial solution. How write a recursive one and store the number in array at the same time? Like when you meet a number which is not zero in array just return it. Please use C code.