fibonacci数列的题目——剑指Offer

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大家都知道斐波那契数列，现在要求输入一个整数n，请你输出斐波那契数列的第n项。

n<=39

class Solution {
public:
    int Fibonacci(int n) {
        if (n < ) return ;
        if (n <= ) return ;
        int fib2 = ;
        int fib1 = ;
        for (int i=; i<=n; i++) {
            int tmp = fib2 + fib1;
            fib2 = fib1;
            fib1 = tmp;
        }
        return fib1;
    }
};