题解 | #斐波那契数列#

class Solution { public: int Fibonacci(int n) {

    if(n<=2)  return 1;
    
    int  first = 1;
    int  second= 1;
    int  sum = 0;
   
    
    for(int i=3;i<=n;i++)
    {
        sum = second + first;
        first  = second;
        second = sum  ;
    }
    return sum;

}

};