【剑指Offer】斐波那契数列

问题描述

算法分析

代码实现

class Solution10 {
public:
    int Fibonacci(int n) {
        if (n == 0){
            return 0;
        }
        if (n == 1){
            return 1;
        }
        int r = 0;
        int r1 = 0,r2=1;
        for (int i = 1; i < n; i++){
            r = r1 + r2;
            r1 = r2;
            r2 = r;
        }
        return r;
    }
};