题目描述

public class Solution {
    
    
    public int Fibonacci(int n) {
    
    
        if(n == 0 || n == 1){
    
    
            return n;
        }
        int a = 0, b = 1, k = 0;
        for(int i = 2; i <= n; i++){
    
    
            k = a + b;
            a = b;
            b = k;
        }
        return k;
    }
}