/*

P125

清单7.15  使用迭代求第N个Fibonacci数

*/

#include <iostream>

int fib(int position);

int main(){

    using namespace std;

    int answer,position;

    cout << "Which position? ";

    cin >> position;

    cout << "\n";

    answer = fib(position);

    cout << answer << "th is the " << position << " Fibonacci number.\n";

    cin >> position;

    return ;

}

int fib(int position){

    if(position < ) return ;

    int last  = ;

    int result = ;

    int tmp = ;

    for(int b = ;b<=position;b++){

        if(b < ) last = ;

            result = last + result;

            tmp = result;

            result = last;

            last = tmp;

    }

    //return result;

}