题解 | #斐波那契数列#

递归

class Solution {
public:
    int Fibonacci(int n) {
        if(n == 0)return 0;
        if(n == 1 || n == 2)return 1;
        return Fibonacci(n-1)+Fibonacci(n-2);
    }
};

迭代

class Solution {
public:
    int Fibonacci(int n) {
        if(n == 0 || n == 1) return n;
        if(n == 2) return 1;
        int pre = 1, cur = 1;
        for(int i=2; i<n; ++i){
            int t = cur;
            cur += pre;
            pre = t;
        }
        return cur;
    }
};