CODEWITHSUNDEEP
c++fibonacci
user2840212
user2840212

Reputation: 3

Need help cleaning up fibonacci sequence using C++ please

I'm still very new to C++ still and decided to make a fibonacci sequence. It worked (Woo!) but it doesn't work as well as I would like it to.

what I mean by that is say for example I told my program to count the first 10 terms of the sequence I will get

"0, 1, 1" and then I have to press enter for each additional number until it hits ten in which case the program returns 0 and ends.

How do I get the program to display all the numbers I want to without hitting enter for each additional one?

Here is my script:

#include <iostream>
using namespace std;

int main()
{
    int FibNum;
    cout << "How many numbers of the Fibonacci Sequence would you like to see? \n\n";
    cin>> FibNum;
    cin.ignore();
    int a = 0;
    int b = 1;
    int c = 2;
    cout << "Fibonacci Sequence up to " << FibNum << " terms.\n\n";
    cout << a << "\n" << b << "\n";

    for (int c = 2; c < FibNum; c++) {
        int d = a + b;
        cout << d;
        cin.ignore();
        a = b;
        b = d;
    }
}

Thanks in advance for any help!

P.s. Also if you notice anything terrible I'm doing please feel free to correct me, I'm very aware I'm probably doing a lot wrong, I'm just trying to learn. :]

Upvotes: 0

Views: 262

Answers (3)

vincent_zhang
vincent_zhang

Reputation: 93

Besides the previous answers,

  1. To better format the output, add white space by changing this

    cout << d;

    to

    cout << d << " ";

  2. You may want to change the type of a, b and d from int to double to prevent overflow.

    (If you let FibNum=100 in your code, you should be able to observe overflow, meaning that you are going to get some incorrect numbers toward the end of the sequence.)

Upvotes: 2

Bathsheba
Bathsheba

Reputation: 234815

A few things:

1) Remove int c = 2; as you're re-defining c inside the for loop.

2) Drop the line cin.ignore();: in your for loop: that will fix your "enter" problem; that line waits for some input then ignores it.

3) Put some white space in your output: e.g. cout << d << ' ' so your numbers are separated.

4) [Acknowledge vincent_zhang] Consider moving to uint64_t as your data type for a, b, and d. This is a standard type in C++11. It's a 64 bit unsigned integer type; adequate for a large number of terms.

and a small thing, bordering on personal opinion,

5) Use ++c instead of c++ as the former will never run slower as, conceptually at least, post-increment has to take a copy of the original value.

Upvotes: 5

Sohil Omer
Sohil Omer

Reputation: 1181

Move cin.ignore() out of the loop then you dont need to enter to print all the 10 numbers of Fibonacci series

Upvotes: 1

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