技術，瞎侃，健康，休閑……

The Fibonacci numbers (0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, ...) are defined by the recurrence:

Write a program to calculate the Fibonacci Numbers.

Input and Output

The input to your program would be a sequence of numbers smaller or equal than 5000, each on a separate line, specifying which Fibonacci number to calculate.

Your program should output the Fibonacci number for each input value, one per line.

Sample Input

5
7
11

Sample Output

The Fibonacci number for 5 is 5
The Fibonacci number for 7 is 13
The Fibonacci number for 11 is 89

Solution

#include <iostream>

using namespace std;

?

int main()

{

?? int first,next,temp,n;

?? while(cin >> n) {

????? first = 0;

????? next = 1;

????? temp = 0;

????? if(n == 0 || n == 1) {

??????? cout << "The Fibonacci number for" << " " << n << " " << "is" << " " << n << endl;

????? }

????? else {

??????? for(inti = 2; i <= n; i++) {

?????????? temp = first + next;

?????????? first = next;

?????????? next = temp;

??????? }

??????? cout << "The Fibonacci number for" << " " << n << " " << "is" << " " << temp << endl;

????? }

?? }

?? return 0;

}