斐波那契数列

#include<iostream>using namespace std;void fib(int n);void fib(int n){int i, sum = 1;int x, y;if (n == 1 || n == 2)cout << sum << endl;else{x = y = 1;for (i = 2; i < n; i++){sum = x + y;x = y;y = sum;}cout << sum << endl;}}int main(){int n;cout << "输入n: ";cin >> n;fib(n);return 0;}