题解 | #小乐乐走台阶#

#include <iostream>
using namespace std;

int func(int n)
{
    int res;
    if (n == 1)
        res = 1;
    else if (n == 2)
        res = 2;
    else 
    {
        int first = 1;
        int second = 2;
        while (n != 2)
        {
            res = first + second;
            first = second;
            second = res;
            n--;
        }
    }
    return res;
}
int main() {
    int n;
    cin >> n;
    int num = func(n);
    cout << num;
}
// 64 位输出请用 printf("%lld")

递归超时了，用的循环