hdoj：2070

Fibbonacci Number

Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 22530    Accepted Submission(s): 10375

Problem Description

Your objective for this question is to develop a program which will generate a fibbonacci number. The fibbonacci function is defined as such:

f(0) = 0
f(1) = 1
f(n) = f(n-1) + f(n-2)

Your program should be able to handle values of n in the range 0 to 50.

 

Input

Each test case consists of one integer n in a single line where 0≤n≤50. The input is terminated by -1.

 

Output

Print out the answer in a single line for each test case.

 

Sample Input

3
4
5
-1

 

Sample Output

2
3
5

Hint

Note:

 
you can use 64bit integer: __int64

费波纳列数

#include <iostream>
using namespace std;

const int limit = 51;
_int64 fib[limit];

int main()
{
    int num;
    fib[0] = 0;
    fib[1] = 1;
    for (int i = 2; i <= limit; i++)
    {
        fib[i] = fib[i - 1] + fib[i - 2];
    }

    while (cin >> num && num!=-1)
    {
        cout << fib[num] << endl;
    }
    return 0;
}